Filed Pursuant to Rule 424(b)(3)
Registration No. 333-254962

To the Shareholders of M&T Bank Corporation and the Stockholders of People’s United Financial, Inc.

MERGER PROPOSED—YOUR VOTE IS VERY IMPORTANT

On behalf of the boards of directors of M&T Bank Corporation (“M&T”) and People’s United Financial, Inc. (“People’s United”), we are pleased to enclose the accompanying joint proxy statement/prospectus relating to the acquisition of People’s United by M&T. We are requesting that you take certain actions as a holder of M&T common stock (an “M&T shareholder” or “shareholder”) or as a holder of People’s United common stock (a “People’s United stockholder” or “stockholder”).

On February 21, 2021, M&T, Bridge Merger Corp., a direct, wholly owned subsidiary of M&T (“Merger Sub”), and People’s United entered into an Agreement and Plan of Merger (as amended from time to time, the “merger agreement”), pursuant to which M&T will, upon the terms and subject to the conditions set forth in the merger agreement, acquire People’s United in an all-stock transaction. The acquisition will create a diversified, community-focused banking franchise with approximately $200 billion in assets and a network of more than 1,100 branches and over 2,000 ATMs that spans 12 states from Maine to Virginia and the District of Columbia.

Under the merger agreement, Merger Sub will merge with and into People’s United, with People’s United as the surviving entity (the “merger”), and as soon as reasonably practicable following the merger, People’s United will merge with and into M&T, with M&T as the surviving entity (the “holdco merger”). At a date and time following the holdco merger as determined by M&T, People’s United Bank, National Association, a national banking association and a wholly owned subsidiary of People’s United, will merge with and into Manufacturers and Traders Trust Company, a New York state chartered bank and a wholly owned subsidiary of M&T (“M&T Bank”), with M&T Bank as the surviving bank (the “bank merger,” and together with the merger and the holdco merger, the “mergers”).

In the merger, People’s United stockholders will receive 0.118 of a share of M&T common stock for each share of People’s United common stock they own. Based on the closing price of M&T’s common stock on the New York Stock Exchange on February 19, 2021, the last trading day before the public announcement of the merger, the exchange ratio represented approximately $17.70 in value for each share of People’s United common stock, representing a merger consideration of approximately $7.6 billion on an aggregate basis.

M&T shareholders will continue to own their existing shares of M&T common stock. The value of the M&T common stock at the time of completion of the merger could be greater than, less than or the same as the value of M&T common stock on the date of the accompanying joint proxy statement/prospectus. We urge you to obtain current market quotations of M&T common stock (trading symbol “MTB”) and People’s United common stock (trading symbol “PBCT”).

In addition, each share of fixed-to-floating rate non-cumulative perpetual preferred stock, Series A, par value $0.01 per share, of People’s United (“People’s United preferred stock”) will be converted into the right to receive a share of a newly created series of preferred stock of M&T, par value $1.00 per share, having terms that are substantially as set forth in Exhibit A to the merger agreement (the “new M&T preferred stock”). The shares of People’s United preferred stock are currently listed on the NASDAQ Global Select Market under the symbol “PBCTP.” The shares of the new M&T preferred stock are expected to be listed on the New York Stock Exchange upon completion of the merger.

We expect the merger and the holdco merger, taken together, will qualify as a reorganization for federal income tax purposes. Accordingly, People’s United stockholders or holders of People’s United preferred stock generally

will not recognize any gain or loss for federal income tax purposes on the exchange of shares of People’s United

common stock or People’s United preferred stock, as applicable, for M&T common stock or new M&T preferred stock, as applicable, in the merger, except with respect to any cash received by such holders in lieu of fractional shares of M&T common stock.

Based on the number of shares of People’s United common stock outstanding as of April 19, 2021, M&T expects to issue approximately 50.4 million shares of M&T common stock to People’s United stockholders in the aggregate in the merger. We estimate that former People’s United stockholders will own approximately 28% and existing M&T shareholders will own approximately 72% of the common stock of M&T following the completion of the merger.

M&T and People’s United will each hold a virtual special meeting of our respective shareholders and stockholders in connection with the merger. At our respective special meetings, in addition to other business, M&T will ask its shareholders to approve the issuance of its common stock to holders of People’s United common stock pursuant to the merger agreement and an amendment to M&T’s charter to effect an increase in the number of authorized shares of M&T’s capital stock and of its preferred stock, and People’s United will ask its stockholders to approve the adoption of the merger agreement. Information about these meetings and the mergers is contained in this document. We urge you to read this document carefully and in its entirety.

Holders of People’s United preferred stock are not entitled to and are not requested to vote at the People’s United special meeting. Holders of M&T preferred stock are not entitled to and are not requested to vote at the M&T special meeting.

The special meeting of People’s United stockholders will be held virtually via the internet on May 25, 2021 at 11:00 A.M., Eastern Time. The special meeting of M&T shareholders will be held virtually via the internet on May 25, 2021 at 11:00 A.M., Eastern Time.

Each of our boards of directors unanimously recommends that holders of common stock vote “FOR” each of the proposals to be considered at the respective meetings. We strongly support this combination of our companies and join our boards in their recommendations.

This joint proxy statement/prospectus provides you with detailed information about the merger agreement and the merger. It also contains or references information about M&T and People’s United and certain related matters. You are encouraged to read this joint proxy statement/prospectus carefully. In particular, you should read the “Risk Factors” section beginning on page 34 for a discussion of the risks you should consider in evaluating the proposed merger and how it will affect you. You can also obtain information about M&T and People’s United from documents that have been filed with the Securities and Exchange Commission that are incorporated into this joint proxy statement/prospectus by reference.

On behalf of the M&T and People’s United boards of directors, thank you for your prompt attention to this important matter.

Sincerely,

René F. Jones Chairman of the Board and Chief Executive Officer M&T Bank Corporation		John P. Barnes Chairman of the Board and Chief Executive Officer People’s United Financial, Inc.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued in connection with the merger or determined if this document is accurate or complete. Any representation to the contrary is a criminal offense.

The securities to be issued in the merger are not savings or deposit accounts or other obligations of any bank or non-bank subsidiary of either M&T or People’s United, and they are not insured by the Federal Deposit Insurance Corporation or any other governmental agency.

The accompanying joint proxy statement/prospectus is dated April 23, 2021, and is first being mailed to M&T shareholders and People’s United stockholders on or about April 26, 2021.

ADDITIONAL INFORMATION

The accompanying joint proxy statement/prospectus incorporates important business and financial information about M&T and People’s United from other documents that are not included in or delivered with this document. This information is available to you without charge upon your written or oral request. You can obtain the documents incorporated by reference in this document through the Securities and Exchange Commission website at http://www.sec.gov or by requesting them in writing, by email or by telephone at the appropriate address below. In addition, documents filed with the Securities and Exchange Commission by M&T are available free of charge by accessing M&T’s website at https://www.mtb.com and documents filed with the Securities and Exchange Commission by People’s United are available free of charge by accessing People’s United’s website at http://www.peoples.com.

You will not be charged for any of these documents that you request. To obtain timely delivery of these documents, you must request them no later than five (5) business days before the date of the applicable special meeting. This means that M&T shareholders requesting documents must do so by May 18, 2021, in order to receive them before the M&T special meeting, and People’s United stockholders requesting documents must do so by May 18, 2021, in order to receive them before the People’s United special meeting.

No one has been authorized to provide you with information that is different from that contained in, or incorporated by reference into, this document. This document is dated April 23, 2021, and you should assume that the information in this document is accurate only as of such date. You should assume that the information incorporated by reference into this document is accurate as of the date of such incorporated document. Neither the mailing of this document to M&T shareholders or People’s United stockholders, nor the issuance by M&T of shares of M&T common stock or new M&T preferred stock pursuant to the merger agreement, will create any implication to the contrary.

This document does not constitute an offer to sell, or a solicitation of an offer to buy, any securities, or the solicitation of a proxy, in any jurisdiction to or from any person to whom it is unlawful to make any such offer or solicitation in such jurisdiction. Except where the context otherwise indicates, information contained in, or incorporated by reference into, this document regarding People’s United has been provided by People’s United and information contained in, or incorporated by reference into, this document regarding M&T has been provided by M&T.

See “Where You Can Find More Information” beginning on page 185 of the accompanying joint proxy statement/prospectus for further information.

M&T Bank Corporation

One M&T Plaza

Buffalo, New York 14203

NOTICE OF VIRTUAL SPECIAL MEETING OF SHAREHOLDERS

To M&T Shareholders:

On February 21, 2021, M&T Bank Corporation, a New York corporation (“M&T”), Bridge Merger Corp., a direct, wholly owned subsidiary of M&T (“Merger Sub”), and People’s United Financial, Inc., a Delaware corporation (“People’s United”), entered into an Agreement and Plan of Merger (as amended from time to time, the “merger agreement”). A copy of the merger agreement is attached as Annex A to the accompanying joint proxy statement/prospectus.

NOTICE IS HEREBY GIVEN that a special meeting of holders of M&T common stock (“M&T shareholders” or “shareholders”) will be held virtually via the internet on May 25, 2021 at 11:00 A.M., Eastern Time (the “M&T special meeting”). We are pleased to notify you of, and invite you, to the M&T special meeting.

At the M&T special meeting, you will be asked to vote on the following matters:

Due to the continuing public health impact of the COVID-19 pandemic and to support the well-being of our shareholders and employees, we are holding the M&T special meeting in a virtual meeting format exclusively by webcast. No physical meeting will be held. As more fully described in the “Questions & Answers” and “The M&T Special Meeting” sections of the accompanying joint proxy statement/prospectus, you are entitled to participate in the M&T special meeting if, as of the close of business on April 19, 2021, you held shares of M&T common stock registered in your name (a “record holder”), or if you held shares through an intermediary, such as a bank or broker, and have a valid legal proxy for the M&T special meeting (a “beneficial owner”). Both record holders and beneficial owners will be able to attend the M&T special meeting online, ask questions and vote during the meeting by visiting www.meetingcenter.io/255180428 and following the instructions. Please have your control number, which can be found on your proxy card, notice or email previously received, to access the meeting. See the “Questions & Answers” section of the accompanying joint proxy statement/prospectus for more information, including technical support information for the virtual M&T special meeting.

The board of directors of M&T has fixed the close of business on April 19, 2021 as the record date for the M&T special meeting. Only holders of record of M&T common stock as of the close of business on the record date for the M&T special meeting are entitled to notice of the M&T special meeting or any adjournment or postponement thereof. Only holders of record of M&T common stock will be entitled to vote at the M&T special meeting or any adjournment or postponement thereof.

M&T has determined that holders of M&T common stock and M&T preferred stock are not entitled to dissenters’ rights with respect to the proposed merger under Section 910 of the New York Business Corporation Law.

The M&T board of directors unanimously recommends that holders of M&T common stock vote “FOR” the M&T charter amendment proposal, “FOR” the M&T share issuance proposal and “FOR” the M&T adjournment proposal.

Your vote is important. We cannot complete the transactions contemplated by the merger agreement unless M&T shareholders approve the M&T charter amendment proposal and the M&T share issuance proposal. The affirmative vote of a majority of the outstanding shares of M&T common stock is required to approve the M&T charter amendment proposal, and a majority of the votes cast by the holders of M&T common stock at the M&T special meeting is required to approve the M&T share issuance proposal.

Whether or not you plan to attend the M&T special meeting, we urge you to please promptly complete, sign, date and return the accompanying proxy card in the enclosed postage-paid envelope or authorize the individuals named on the accompanying proxy card to vote your shares by calling the toll-free telephone number or by using the internet as described in the instructions included with the accompanying proxy card. If your shares are held in the name of a bank, broker, trustee or other nominee, please follow the instructions on the voting instruction card furnished by such bank, broker, trustee or other nominee.

By Order of the Board of Directors

René F. Jones

Chairman of the Board and Chief Executive Officer

M&T Bank Corporation

April 23, 2021

People’s United Financial, Inc.

850 Main Street

Bridgeport, Connecticut 06604

NOTICE OF VIRTUAL SPECIAL MEETING OF STOCKHOLDERS

To People’s United Stockholders:

On February 21, 2021, People’s United Financial, Inc., a Delaware corporation (“People’s United”), M&T Bank Corporation, a New York corporation (“M&T”), and Bridge Merger Corp., a direct, wholly owned subsidiary of M&T (“Merger Sub”), entered into an Agreement and Plan of Merger (the “merger agreement”). A copy of the merger agreement is attached as Annex A to the accompanying joint proxy statement/prospectus.

NOTICE IS HEREBY GIVEN that a special meeting of holders of People’s United common stock (“People’s United stockholders” or “stockholders”) will be held virtually via the internet on May 25, 2021 at 11:00 A.M., Eastern Time (the “People’s United special meeting”). We are pleased to notify you of and invite you to the People’s United special meeting.

At the People’s United special meeting, People’s United stockholders will be asked to vote on the following matters:

In light of the ongoing developments related to the COVID-19 pandemic and to support the health and well-being of our stockholders, employees and community, the People’s United special meeting will be held in a virtual-only format conducted via live webcast. You will be able to attend the special meeting by visiting www.virtualshareholdermeeting.com/PBCT2021SM (the “People’s United special meeting website”) and inserting the 16-digit control number included in your proxy card or, if you hold your shares of People’s United common stock in “street name,” in the voting instruction form provided by your bank, broker, trustee, nominee or other holder of record. You will be able to vote your shares electronically over the internet and submit questions online during the meeting by logging in to the website listed above and using the 16-digit control number. See the “Questions & Answers” section of the accompanying joint proxy statement/prospectus for more information, including technical support information for the virtual People’s United special meeting.

The board of directors of People’s United has fixed the close of business on April 19, 2021 as the record date for the People’s United special meeting. Only holders of record of People’s United common stock as of the close of business on the record date for the People’s United special meeting are entitled to notice of the People’s United special meeting or any adjournment or postponement thereof. Only holders of record of People’s United common stock will be entitled to vote at the People’s United special meeting or any adjournment or postponement thereof.

People’s United has determined that holders of People’s United common stock and People’s United preferred stock are not entitled to appraisal rights with respect to the proposed merger under Section 262 of the Delaware General Corporation Law.

The People’s United board of directors unanimously recommends that People’s United stockholders vote “FOR” the People’s United merger proposal, “FOR” the People’s United compensation proposal and “FOR” the People’s United adjournment proposal.

Your vote is important. We cannot complete the transactions contemplated by the merger agreement unless People’s United stockholders approve the People’s United merger proposal. The affirmative vote of a majority of the outstanding shares of People’s United common stock is required to approve the People’s United merger proposal.

Whether or not you plan to attend the People’s United special meeting, we urge you to please promptly complete, sign, date and return the accompanying proxy card in the enclosed postage-paid envelope or authorize the individuals named on the accompanying proxy card to vote your shares by calling the toll-free telephone number or by using the internet as described in the instructions included with the accompanying proxy card. If your shares are held in the name of a bank, broker, trustee or other nominee, please follow the instructions on the voting instruction card furnished by such bank, broker, trustee or other nominee.

By Order of the Board of Directors

John P. Barnes

Chairman of the Board and Chief Executive Officer

People’s United Financial, Inc.

April 23, 2021

TABLE OF CONTENTS

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QUESTIONS AND ANSWERS

The following are some questions that you may have about the merger and the M&T special meeting or the People’s United special meeting, and brief answers to those questions. We urge you to read carefully the remainder of this joint proxy statement/prospectus because the information in this section does not provide all of the information that might be important to you with respect to the merger, the M&T special meeting or the People’s United special meeting. Additional important information is also contained in the documents incorporated by reference into this joint proxy statement/prospectus. See “Where You Can Find More Information” beginning on page 185.

In this joint proxy statement/prospectus, unless the context otherwise requires:

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In order to complete the merger, among other things:

M&T is holding a virtual special meeting of M&T shareholders (the “M&T special meeting”) to obtain approval of the M&T charter amendment proposal and the M&T share issuance proposal. Holders of M&T preferred stock are not entitled to and are not requested to vote at the M&T special meeting.

M&T shareholders will also be asked to approve the proposal to adjourn the M&T special meeting to solicit additional proxies (i) if there are insufficient votes at the time of the M&T special meeting to approve the M&T charter amendment proposal and/or the M&T share issuance proposal or (ii) if adjournment is necessary or appropriate to ensure that any supplement or amendment to this joint proxy statement/prospectus is timely provided to M&T shareholders (the “M&T adjournment proposal”).

People’s United is holding a virtual special meeting of People’s United stockholders (the “People’s United special meeting”) to obtain approval of the People’s United merger proposal. Holders of People’s United preferred stock are not entitled to and are not requested to vote at the People’s United special meeting.

People’s United stockholders will also be asked to approve, on an advisory (non-binding) basis, the merger-related compensation payments that will or may be paid to the named executive officers of People’s United in connection with the transactions contemplated by the merger agreement (the “People’s United compensation proposal”), and to approve the proposal to adjourn the People’s United special meeting to solicit additional proxies (i) if there are insufficient votes at the time of the People’s United special meeting, to approve the People’s United merger proposal or (ii) if adjournment is necessary or appropriate, to ensure that any supplement or amendment to this joint proxy statement/prospectus is timely provided to holders of People’s United common stock (the “People’s United adjournment proposal”).

This document is also a prospectus that is being delivered to holders of People’s United common stock and holders of People’s United preferred stock because, pursuant to the merger agreement, M&T is offering shares of M&T common stock to People’s United stockholders and is also issuing shares of new M&T preferred stock to holders of People’s United preferred stock.

This joint proxy statement/prospectus contains important information about the merger and the other proposals being voted on at the M&T and People’s United special meetings. You should read it carefully and in its entirety. The enclosed materials allow you to have your shares of common stock voted by proxy

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without attending your meeting. Your vote is important and we encourage you to submit your proxy as soon as possible.

Each share of People’s United common stock issued and outstanding immediately prior to the effective time including each People’s United restricted share (as defined below) held by a non-employee director of the People’s United board of directors (each, a “People’s United director restricted share”) and except for certain shares owned by M&T or People’s United, will be converted into the right to receive 0.118 of a share (the “exchange ratio”) of M&T common stock (the “merger consideration”). After completion of the merger, (1) People’s United will no longer be a public company, (2) People’s United common stock and People’s United preferred stock will be delisted from the NASDAQ Global Select Market (“NASDAQ”) and will cease to be publicly traded, and (3) the People’s United common stock and People’s United preferred stock will be deregistered under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). After completion of the holdco merger, People’s United will cease to exist. Holders of M&T common stock and M&T preferred stock will continue to own their existing shares of M&T common stock and M&T preferred stock, respectively. See the information provided in the section entitled “The Merger Agreement—Structure of the Merger” beginning on page 119 and the merger agreement for more information about the merger.

The People’s United special meeting will be held virtually via the internet on May 25, 2021 at 11:00 A.M., Eastern time.

Even if you plan to attend your respective company’s special meeting virtually, M&T and People’s United recommend that you vote your shares in advance as described below so that your vote will be counted if you later decide not to or become unable to attend the applicable special meeting.

At the People’s United special meeting, People’s United stockholders will be asked to consider and vote on the following proposals:

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In order to complete the merger, among other things, M&T shareholders must approve the M&T charter amendment proposal and the M&T share issuance proposal, and People’s United stockholders must approve the People’s United merger proposal. None of the approvals of the M&T adjournment proposal, the People’s United compensation proposal or the People’s United adjournment proposal is a condition to the obligations of M&T or People’s United to complete the merger.

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The merger agreement also provides that, at the effective time, each outstanding performance share unit (a “People’s United performance share”) under the People’s United stock plans, whether vested or unvested, will, automatically and without any action on the part of the holder thereof, cease to represent a performance share unit denominated in shares of People’s United common stock and will be converted into a restricted share unit denominated in shares of M&T common stock (an “M&T stock-based RSU”). The number of shares of M&T common stock subject to each such M&T stock-based RSU will be equal to the product (rounded up or down to the nearest whole number, with 0.5 rounding up) of (i) the number of shares of People’s United common stock subject to such People’s United performance share immediately prior to the effective time (including any applicable dividend equivalents) based on the higher of target performance and actual performance through the effective time as reasonably determined by the compensation committee of the People’s United board of directors in its reasonable judgment and in consultation with M&T, multiplied by (ii) the exchange ratio. Except as specifically provided in the merger agreement, at and following the effective time, each such M&T stock-based RSU will continue to be governed by the same terms and conditions (including employment vesting terms but excluding performance conditions, after giving effect to any “change in control” post-termination protections under the applicable People’s United stock plan or award agreement) as were applicable to the applicable People’s United performance share immediately prior to the effective time.

The merger agreement further provides that, at the effective time, each outstanding option to purchase shares of People’s United common stock (a “People’s United option” and together with the People’s United restricted shares and People’s United performance shares, the “People’s United equity awards”) under the People’s United stock plans, whether vested or unvested, will, automatically and without any action on the part of the holder thereof, cease to represent an option to purchase shares of People’s United common stock and will be converted into an option to purchase a number of shares of M&T common stock (an “M&T option,” and together with the M&T restricted shares and M&T stock-based RSUs, the “M&T converted equity awards”) equal to the product (rounded down to the nearest whole number) of (i) the number of shares of People’s United common stock subject to such People’s United option immediately prior to the effective time and (ii) the exchange ratio, at an exercise price per share (rounded up to the nearest whole cent) equal to (a) the exercise price per share of People’s United common stock of such People’s United option immediately prior to the effective time divided by (b) the exchange ratio; provided, however, that the exercise price and the number of shares of M&T common stock purchasable pursuant to the People’s United options will be determined in a manner consistent with the requirements of Section 409A of the Internal Revenue Code of 1986, as amended (the “Code”); provided, further, that in the case of any People’s United option to which Section 422 of the Code applies, the exercise price and the number of shares of People’s United common stock purchasable pursuant to such option will be determined in accordance with the foregoing, subject to such adjustments as are necessary in order to satisfy the requirements of Section 424(a) of the Code.

Except as specifically provided in the merger agreement or in the confidential disclosure schedules, following the effective time, each People’s United option will continue to be governed by the same terms and conditions (including vesting and exercisability terms, after giving effect to any “change in control” post-termination protections under the applicable People’s United stock plan or award agreement) as were applicable to such People’s United option immediately prior to the effective time.

The merger agreement also provides that, in the event of a “Change in Control” (as defined in M&T’s 2019 Equity Incentive Compensation Plan (the “M&T equity plan”)) following the closing, any then-outstanding

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M&T converted equity award, to the extent not then vested, will be treated in accordance with Section 10.1 of the M&T equity plan.

In connection with the termination of the ESOP and the merger, People’s United will cause all outstanding indebtedness of the ESOP (including any loan made to the ESOP) to be satisfied in full at least five (5) business days prior to the closing date. People’s United will cancel or offset any loan made to the ESOP (including accrued interest thereon) in exchange for unallocated shares attributable to such loan having an aggregate fair market value that is not more than the outstanding amount of such loan plus accrued interest. This will result in the cancellation of both the loan receivable and payable on the books of People’s United. Any remaining shares of People’s United common stock held by the ESOP trust after repayment of any loan made to the ESOP will be converted into shares of M&T common stock in accordance with the terms of the merger agreement, and the balance of the unallocated shares and any other unallocated assets remaining in the ESOP’s suspense account after satisfaction of such loan and conversion of the shares of People’s United common stock into M&T common stock will be allocated as earnings to the accounts of the ESOP participants who are employed as of the date of termination of the ESOP based on

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their account balances under the ESOP as of such date. For the avoidance of doubt, the immediately preceding sentence will have no effect if there are no such unallocated shares or any other unallocated assets remaining in the ESOP’s suspense account. Prior to the closing date, People’s United will provide M&T documentary evidence sufficient to show that all outstanding indebtedness of People’s United’s ESOP (including any loan made to the ESOP) has been satisfied in full.

As soon as practicable after the closing date, M&T will file or cause to be filed all necessary documents with the Internal Revenue Service (the “IRS”) for a determination letter for termination of the ESOP. As soon as practicable following the receipt of a favorable determination letter from the IRS regarding the qualified status of the ESOP upon its termination, the account balances in the ESOP will either be distributed to participants and beneficiaries or transferred to an eligible tax qualified retirement plan or individual retirement account as a participant or beneficiary may direct. Prior to the distribution of account balances in the ESOP, M&T will take any and all actions as may be required, including amendments to the M&T 401(k) plan to permit each continuing employee to make rollover contributions of “eligible rollover distributions” (within the meaning of Section 401(a)(31) of the Code) at the time of such distribution from the ESOP in an amount equal to the full account balance distributed to such continuing employee from the ESOP to the M&T 401(k) plan.

In considering the recommendations of the People’s United board of directors, People’s United stockholders should be aware that People’s United directors and executive officers may have interests in the merger that are different from, or in addition to, the interests of People’s United stockholders generally. For a more complete description of these interests, see the information provided in the section entitled “The Merger—Interests of Certain People’s United Directors and Executive Officers in the Merger” beginning on page 104.

Each holder of M&T common stock is entitled to cast one (1) vote on each matter properly brought before the M&T special meeting for each share of M&T common stock that such holder owned of record as of the record date. As of April 19, 2021, there were 128,645,421 outstanding shares of M&T common stock.

Attendance at the special meeting is not required to vote. See below and the section entitled “The M&T Special Meeting—Proxies” beginning on page 44 for instructions on how to vote your shares without attending the M&T special meeting.

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Each holder of People’s United common stock is entitled to cast one (1) vote on each matter properly brought before the People’s United special meeting for each share of People’s United common stock that such holder owned of record as of the record date. As of April 19, 2021, there were 427,394,600 outstanding shares of People’s United common stock.

Attendance at the special meeting is not required to vote. See below and the section entitled “The People’s United Special Meeting—Proxies” beginning on page 51 for instructions on how to vote your shares of People’s United common stock without attending the People’s United special meeting.

M&T Proposal 2: M&T share issuance proposal. Approval of the M&T share issuance proposal requires the affirmative vote of a majority of votes cast by M&T shareholders at the M&T special meeting. Accordingly, an abstention or a broker non-vote or other failure to vote will have no effect on the outcome of the M&T share issuance proposal.

M&T Proposal 3: M&T adjournment proposal. Whether or not a quorum will be present at the meeting, approval of the M&T adjournment proposal requires the affirmative vote of a majority of the votes cast by M&T shareholders at the M&T special meeting. Accordingly, an abstention or a broker non-vote or other failure to vote will have no effect on the outcome of the M&T adjournment proposal.

People’s United Proposal 2: People’s United compensation proposal. Approval of the People’s United compensation proposal requires the affirmative vote of a majority of the votes cast by People’s United stockholders. Accordingly, an abstention or a broker non-vote or other failure to vote will have no effect on the outcome of the People’s United compensation proposal.

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People’s United Proposal 3: People’s United adjournment proposal. Whether or not a quorum will be present at the meeting, approval of the People’s United adjournment proposal requires the affirmative vote of a majority of the votes cast by People’s United stockholders. Accordingly, an abstention or a broker non-vote or other failure to vote will have no effect on the outcome of the People’s United adjournment proposal.

Beneficial Owners. If you hold shares in a brokerage or other account in “street name” you are a “beneficial owner” and your shares may be voted at the M&T special meeting or the People’s United special meeting, as applicable by you as described below. If you choose to vote your shares virtually at the respective special meeting via the applicable special meeting website, you will need the control number, as described below

M&T special meeting. If you are a record holder you will be able to attend the M&T special meeting online, ask questions and vote during the meeting by visiting www.meetingcenter.io/255280428 and following the instructions. Please have your control number, which can be found on your proxy card, notice or email previously received, to access the meeting. If you are a beneficial owner, you also will be able to attend the

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M&T special meeting online, ask questions and vote during the meeting by visiting www.meetingcenter.io/255180428 and following the instructions. Please have your control number, which can be found on your proxy card, notice or email previously received, to access the meeting. Please review this information prior to the M&T special meeting to ensure you have access.

M&T encourages its shareholders to visit the meeting website above in advance of the M&T special meeting to familiarize themselves with the online access process. The virtual M&T special meeting platform is fully supported across browsers and devices that are equipped with the most updated version of applicable software and plugins. Shareholders should verify their internet connection prior to the M&T special meeting. Shareholders encountering difficulty with the M&T special meeting virtual platform during the sign-in process or at any time during the meeting may utilize technical support provided by M&T through Computershare. Technical support information is provided on the sign-in page for all shareholders. If you have difficulty accessing the virtual M&T special meeting during check-in or during the meeting, please contact technical support as indicated on the M&T special meeting sign-in page. Shareholders will have substantially the same opportunities to participate in the virtual M&T special meeting as they would have at a physical, in-person meeting. Shareholders as of the record date will be able to attend, vote, examine the shareholder list, and submit questions during a portion of the meeting via the online platform.

People’s United special meeting. If you are a record holder you will be able to attend the People’s United special meeting online, ask questions and vote during the meeting by visiting www.virtualshareholdermeeting.com/PBCT2021SM and following the instructions. Please have your 16-digit control number, which can be found on your proxy card, notice or email previously received, to access the meeting. If you are a beneficial owner, you also will be able to attend the People’s United special meeting online, ask questions and vote during the meeting by visiting www.virtualshareholdermeeting.com/PBCT2021SM and following the instructions. Please have your 16-digit control number, which can be found on the voting instructions provided by your bank, broker, trustee or other nominee, to access the meeting. Please review this information prior to the People’s United special meeting to ensure you have access.

People’s United encourages its stockholders to visit the meeting website above in advance of the People’s United special meeting to familiarize themselves with the online access process. The virtual People’s United special meeting platform is fully supported across browsers and devices that are equipped with the most updated version of applicable software and plugins. Stockholders should verify their internet connection prior to the People’s United special meeting. If you have difficulty accessing the virtual People’s United special meeting during check-in or during the meeting, please contact technical support as indicated on the People’s United special meeting sign-in page. Stockholders will have substantially the same opportunities to participate in the virtual People’s United special meeting as they would have at a physical, in-person meeting. Stockholders as of the record date will be able to attend, vote, examine the stockholder list, and submit questions during a portion of the meeting via the online platform.

Even if you plan to attend the M&T special meeting or the People’s United special meeting virtually, as applicable, M&T and People’s United recommend that you vote your shares in advance as described below so that your vote will be counted if you later decide not to or become unable to attend the respective special meeting.

Additional information on attending the virtual special meetings can be found under the section entitled “The M&T Special Meeting—Attending the Virtual Special Meeting” on page 43 and under the section entitled “The People’s United Special Meeting—Attending the Virtual Special Meeting” on page 50.

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If you are a record holder of M&T common stock or People’s United common stock, you can vote your shares by proxy over the internet, by telephone or by mail by following the instructions provided in the enclosed proxy card. If you hold shares beneficially in “street name” as a beneficial owner of M&T common stock or People’s United common stock, you should follow the voting instructions provided by your bank, broker, trustee or other nominee.

Additional information on voting procedures can be found under the section entitled “The M&T Special Meeting—Attending the Virtual Special Meeting” on page 43 and under the section entitled “The People’s United Special Meeting—Attending the Virtual Special Meeting” on page 50.

The M&T board of directors and the People’s United board of directors unanimously recommend that you vote “FOR” the M&T charter amendment proposal and “FOR” the People’s United merger proposal, respectively, and “FOR” the other proposals to be considered at the M&T special meeting and the People’s United special meeting, respectively.

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Under the terms of the People’s United 401(k) plan, the People’s United 401(k) plan trustee votes the shares of People’s United common stock held by the plan only in accordance with instructions provided to the trustee on how to vote the shares by a participant with respect to the shares of People’s United common stock held in such participant’s plan account. The People’s United 401(k) plan trustee will vote your shares of People’s United common stock in accordance with your instructions. In the event such written instructions direct the voting of fractional shares, the People’s United 401(k) plan trustee will cumulate fractional share votes and vote all resulting whole share votes. Any remaining partial share votes will be disregarded. Any shares of People’s United common stock held by the People’s United 401(k) plan for which the trustee has not received written instructions will not be voted. The deadline for returning your voting instructions for shares held in your account in the People’s United 401(k) plan is three days prior to the People’s United special meeting date.

Under the terms of the ESOP, the ESOP trustee votes all shares of People’s United common stock held by the ESOP, but each participant may provide instructions to the trustee on how to vote the shares of People’s United common stock held in such participant’s plan account. The ESOP trustee will vote your shares of People’s United common stock in accordance with your instructions and, subject to the exercise of its fiduciary responsibilities, will vote all unallocated shares of People’s United common stock held by the ESOP and allocated shares of People’s United common stock for which no voting instructions were received in the same proportion as the instructions received from other participants in the ESOP. The deadline for returning your voting instructions for shares held in your account in the ESOP is ten (10) days prior to the People’s United special meeting date.

If you are a beneficial owner and your shares are held by a bank, broker, trustee or other nominee, you may change your vote by:

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Record Holders. For shares held directly, please complete, sign, date and return each proxy card (or cast your vote by telephone or internet as provided on each proxy card) or otherwise follow the voting instructions provided in this joint proxy statement/prospectus in order to ensure that all of your shares of M&T common stock or People’s United common stock are voted.

Beneficial Owners. For shares held in “street name” through a bank, broker, trustee or other nominee, you should follow the procedures provided by your bank, broker, trustee or other nominee in order to vote your shares.

People’s United stockholders: If you have any questions about the merger or how to submit your proxy or voting instruction card, or if you need additional copies of this document or the enclosed proxy card or voting instruction card, you should contact People’s United’s proxy solicitor, D.F. King & Co., Inc., by calling toll-free at (800) 207-3159.

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RISK FACTORS

In addition to the other information contained in or incorporated by reference into this joint proxy statement/prospectus, including the matters addressed under the caption “Cautionary Statement Regarding Forward-Looking Statements” beginning on page 32, People’s United stockholders should carefully consider the following risk factors in deciding whether to vote for the approval of the People’s United merger proposal, and M&T shareholders should carefully consider the following risk factors in deciding whether to vote for the approval of the M&T charter amendment proposal and the M&T share issuance proposal.

Risks Relating to the Consummation of the Merger and M&T Following the Merger

Because the market price of M&T common stock may fluctuate, People’s United stockholders cannot be certain of the market value of the merger consideration they will receive.

In the merger, each share of People’s United common stock issued and outstanding immediately prior to the effective time, including each People’s United director restricted share and except for certain shares owned by M&T or People’s United, will be converted into 0.118 of a share of M&T common stock. This exchange ratio is fixed and will not be adjusted for changes in the market price of either M&T common stock or People’s United common stock. Changes in the price of M&T common stock between now and the time of the merger will affect the value that People’s United stockholders will receive in the merger. Neither M&T nor People’s United is permitted to terminate the merger agreement as a result of any increase or decrease in the market price of M&T common stock or People’s United common stock.

Stock price changes may result from a variety of factors, including general market and economic conditions, changes in People’s United’s and M&T’s businesses, operations and prospects, the recent volatility in the prices of securities in global financial markets, including market prices of People’s United, M&T and other banking companies, the effects of the COVID-19 pandemic and regulatory considerations, many of which are beyond People’s United’s and M&T’s control. Therefore, at the time of the M&T special meeting and the People’s United special meeting, M&T shareholders and People’s United stockholders will not know the market value of the consideration that People’s United stockholders will receive at the effective time. You should obtain current market quotations for shares of M&T common stock and for shares of People’s United common stock.

The market price of M&T common stock after the merger may be affected by factors different from those currently affecting the market price of shares of People’s United common stock or M&T common stock.

In the merger, People’s United stockholders will become M&T shareholders. M&T’s business differs from that of People’s United. Accordingly, the results of operations of M&T and the market price of M&T common stock after the completion of the merger may be affected by factors different from those currently affecting the independent results of operations of each of M&T and People’s United. For a discussion of the businesses of M&T and People’s United and of certain factors to consider in connection with those businesses, see the documents incorporated by reference in this joint proxy statement/prospectus and referred to under “Where You Can Find More Information” beginning on page 185.

The opinion delivered by Lazard to M&T’s board of directors and the opinions delivered by KBW and J.P. Morgan to People’s United’s board of directors, respectively, prior to the entry into the merger agreement will not reflect changes in circumstances that may have occurred since the dates of the opinions.

The opinion from Lazard, which is M&T’s financial advisor, to M&T’s board of directors, and the opinions from KBW and J.P. Morgan, which are People’s United’s financial advisors, to People’s United’s board of directors were all delivered on and dated either February 19, 2021 or February 20, 2021. Changes in the operations and prospects of M&T or People’s United, general market and economic conditions and other factors which may be beyond the control of M&T and People’s United, including the ongoing effects of the COVID-19 pandemic on

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such market and economic conditions, and the market prices of M&T and People’s United, may have altered the value of M&T or People’s United or the prices of shares of M&T common stock and shares of People’s United common stock as of the date of this joint proxy statement/prospectus, or may alter such values and prices by the time the merger is completed. The opinions do not speak as of the date of this joint proxy statement/prospectus or as of any other date subsequent to the dates of those opinions.

Combining M&T and People’s United may be more difficult, costly or time-consuming than expected, and M&T and People’s United may fail to realize the anticipated benefits of the merger.

The success of the merger will depend, in part, on the ability to realize the anticipated cost savings from combining the businesses of M&T and People’s United. To realize the anticipated benefits and cost savings from the merger, which are expected to be approximately $330 million in annual pre-tax cost savings, M&T and People’s United must integrate and combine their businesses in a manner that permits those cost savings to be realized, without adversely affecting current revenues and future growth. If M&T and People’s United are not able to successfully achieve these objectives, the anticipated benefits of the merger may not be realized fully or at all or may take longer to realize than expected. In addition, the actual cost savings of the merger could be less than anticipated, and integration may result in additional and unforeseen expenses.

An inability to realize the full extent of the anticipated benefits of the merger and the other transactions contemplated by the merger agreement, as well as any delays encountered in the integration process, could have an adverse effect upon the revenues, levels of expenses and operating results of M&T following the completion of the merger, which may adversely affect the value of the common stock of M&T following the completion of the merger.

M&T and People’s United have operated and, until the completion of the merger, must continue to operate, independently. It is possible that the integration process could result in the loss of key employees, the disruption of each company’s ongoing businesses or inconsistencies in standards, controls, procedures and policies that adversely affect the companies’ ability to maintain relationships with clients, customers, depositors and employees or to achieve the anticipated benefits and cost savings of the merger. Integration efforts between the two companies may also divert management attention and resources. These integration matters could have an adverse effect on each of M&T and People’s United during this transition period and on M&T for an undetermined period after completion of the merger.

The COVID-19 pandemic may delay and adversely affect the completion of the merger.

The COVID-19 pandemic has created economic and financial disruptions that have adversely affected, and are likely to continue to adversely affect, the business, financial condition, liquidity, capital and results of operations of M&T and People’s United. If the effects of the COVID-19 pandemic cause a continued or extended decline in the economic environment and the financial results of M&T or People’s United, or the business operations of M&T or People’s United are further disrupted as a result of the COVID-19 pandemic, efforts to complete the merger and integrate the businesses of M&T and People’s United may also be delayed and adversely affected. Additional time may be required to obtain the requisite regulatory approvals, and the Federal Reserve Board, the NYDFS, the CTDOB and/or other regulators may impose additional requirements on M&T or People’s United that must be satisfied prior to completion of the merger, which could delay and adversely affect the completion of the merger.

M&T may be unable to retain M&T and/or People’s United personnel successfully after the merger is completed.

The success of the merger will depend in part on M&T’s ability to retain the talents and dedication of key employees currently employed by M&T and People’s United. It is possible that these employees may decide not to remain with M&T or People’s United, as applicable, while the merger is pending or with M&T after the

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merger is completed. If M&T and People’s United are unable to retain key employees, including management, who are critical to the successful integration and future operations of the companies, M&T and People’s United could face disruptions in their operations, loss of existing customers, loss of key information, expertise or know-how and unanticipated additional recruitment costs. In addition, following the merger, if key employees terminate their employment, M&T’s business activities may be adversely affected, and management’s attention may be diverted from successfully integrating M&T and People’s United to hiring suitable replacements, all of which may cause M&T’s business to suffer. In addition, M&T and People’s United may not be able to locate or retain suitable replacements for any key employees who leave either company.

Regulatory approvals may not be received, may take longer than expected, or may impose conditions that are not presently anticipated or that could have an adverse effect on M&T following the merger.

Before the mergers may be completed, various approvals, consents and non-objections must be obtained from the Federal Reserve Board, the NYDFS, the CTDOB, and other regulatory authorities. In determining whether to grant these approvals, such regulatory authorities consider a variety of factors, including the regulatory standing of each party and the factors described under “The Merger—Regulatory Approvals” beginning on page 112. These approvals could be delayed or not obtained at all, including due to: an adverse development in either party’s regulatory standing or in any other factors considered by regulators when granting such approvals, including factors not known as of the date of this joint proxy statement/prospectus and factors that may arise in the future; governmental, political or community group inquiries, investigations or opposition; or changes in legislation or the political environment generally. The Federal Reserve Board has stated that if material weaknesses are identified by examiners before a banking organization applies to engage in expansionary activity, the Federal Reserve Board will expect the banking organization to resolve all such weaknesses before applying for such expansionary activity. The Federal Reserve Board has also stated that if issues arise during the processing of an application for expansionary activity, it will expect the applicant banking organization to withdraw its application pending resolution of any supervisory concerns.

The approvals that are granted may impose terms and conditions, limitations, obligations or costs, or place restrictions on the conduct of M&T’s business or require changes to the terms of the transactions contemplated by the merger agreement. There can be no assurance that regulators will not impose any such conditions, limitations, obligations or restrictions and that such conditions, limitations, obligations or restrictions will not have the effect of delaying the completion of any of the transactions contemplated by the merger agreement, imposing additional material costs on or materially limiting the revenues of M&T following the merger or otherwise reduce the anticipated benefits of the merger if the merger were consummated successfully within the expected timeframe. In addition, there can be no assurance that any such conditions, terms, obligations or restrictions will not result in the delay or abandonment of the merger. Additionally, the completion of the merger is conditioned on the absence of certain orders, injunctions or decrees by any court or regulatory agency of competent jurisdiction that would prohibit or make illegal the completion of any of the transactions contemplated by the merger agreement.

In addition, despite the parties’ commitments to use their reasonable best efforts to comply with conditions imposed by regulators, under the terms of the merger agreement, M&T will not be required, and People’s United will not be permitted without M&T’s prior written consent, to take actions or agree to conditions in connection with obtaining the foregoing permits, consents, approvals and authorizations of governmental entities that would reasonably be expected to have a material adverse effect on M&T and its subsidiaries, taken as a whole, after giving effect to the merger. See “The Merger—Regulatory Approvals” beginning on page 112.

The unaudited pro forma combined condensed financial information included in this joint proxy statement/prospectus is preliminary and the actual purchase price as well as the actual financial condition and results of operations of M&T after the merger may differ materially.

The unaudited pro forma combined condensed financial information in this joint proxy statement/prospectus is presented for illustrative purposes only and is not necessarily indicative of what M&T’s actual financial

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condition or results of operations would have been had the merger been completed on the dates indicated. The unaudited pro forma combined condensed financial information reflects adjustments, which are based upon preliminary estimates, to record the People’s United identifiable assets acquired and liabilities assumed at fair value and the resulting goodwill recognized. The purchase price allocation reflected in this document is preliminary, and final allocation of the purchase price will be based upon the actual purchase price and the fair value of the assets and liabilities of People’s United as of the date of the completion of the merger. Accordingly, the actual purchase price may vary significantly from the purchase price used in preparing the unaudited pro forma combined condensed financial information in this document. Accordingly, the final acquisition accounting adjustments may differ materially from the pro forma adjustments reflected in this document. For more information, see “Unaudited Pro Forma Combined Condensed Financial Statements” beginning on page 144.

Certain of People’s United’s directors and executive officers may have interests in the merger that may differ from the interests of People’s United stockholders.

People’s United stockholders should be aware that some of People’s United’s directors and executive officers may have interests in the merger and have arrangements that are different from, or in addition to, those of People’s United stockholders. These interests and arrangements may create potential conflicts of interest. The People’s United board of directors was aware of these respective interests and considered these interests, among other matters, when making its decisions to approve the merger agreement, and in recommending that People’s United stockholders vote to adopt the merger agreement. For a more complete description of these interests, please see “The Merger—Interests of Certain People’s United Directors and Executive Officers in the Merger” beginning on page 104.

The merger agreement may be terminated in accordance with its terms and the merger may not be completed.

The merger agreement is subject to a number of conditions which must be fulfilled in order to complete the merger. Those conditions include: (1) approval by People’s United stockholders of the People’s United merger proposal and the approval by M&T’s shareholders of the M&T charter amendment proposal and the M&T share issuance proposal; (2) authorization for listing on the NYSE of the shares of M&T common stock and new M&T preferred stock to be issued in the merger, subject to official notice of issuance; (3) the receipt of required regulatory approvals, including the approval of the Federal Reserve Board, the NYDFS and the CTDOB; (4) effectiveness of the registration statement on Form S-4 of which this joint proxy statement/prospectus forms a part; and (5) the absence of any order, injunction, decree or other legal restraint preventing the completion of the merger, the holdco merger, the bank merger or any of the other transactions contemplated by the merger agreement or making the completion of the merger, the holdco merger, the bank merger or any of the other transactions contemplated by the merger agreement illegal. Each party’s obligation to complete the merger is also subject to certain additional customary conditions, including (a) subject to certain exceptions, the accuracy of the representations and warranties of the other party, (b) the performance in all material respects by the other party of its obligations under the merger agreement and (c) the receipt by such party of an opinion from its counsel to the effect that the merger and the holdco merger, taken together, will qualify as a reorganization within the meaning of Section 368(a) of the Code.

These conditions to the closing may not be fulfilled in a timely manner or at all, and, accordingly, the merger may not be completed. In addition, the parties can mutually decide to terminate the merger agreement at any time, before or after shareholder approval, or M&T or People’s United may elect to terminate the merger agreement in certain other circumstances. See “The Merger Agreement—Termination of the Merger Agreement” beginning on page 137.

Failure to complete the merger could negatively impact M&T or People’s United.

If the merger is not completed for any reason, including as a result of M&T shareholders failing to approve either the M&T charter amendment proposal or the M&T share issuance proposal or People’s United stockholders

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failing to approve the People’s United merger proposal, there may be various adverse consequences and M&T and/or People’s United may experience negative reactions from the financial markets and from their respective customers and employees. For example, M&T’s or People’s United’s businesses may have been impacted adversely by the failure to pursue other beneficial opportunities due to the focus of management on the merger, without realizing any of the anticipated benefits of completing the merger. Additionally, if the merger agreement is terminated, the market price of M&T common stock or People’s United common stock could decline to the extent that current market prices reflect a market assumption that the merger will be beneficial and will be completed. M&T and/or People’s United also could be subject to litigation related to any failure to complete the merger or to proceedings commenced against M&T or People’s United to perform their respective obligations under the merger agreement. If the merger agreement is terminated under certain circumstances, either M&T or People’s United may be required to pay a termination fee of $280 million to the other party.

Additionally, each of M&T and People’s United has incurred and will incur substantial expenses in connection with the negotiation and completion of the transactions contemplated by the merger agreement, as well as the costs and expenses of preparing, filing, printing and mailing this joint proxy statement/prospectus, and all filing and other fees paid in connection with the merger. If the merger is not completed, M&T and People’s United would have to pay these expenses without realizing the expected benefits of the merger.

M&T and People’s United will be subject to business uncertainties and contractual restrictions while the merger is pending.

Uncertainty about the effect of the merger on employees and customers may have an adverse effect on M&T and People’s United. These uncertainties may impair M&T’s or People’s United’s ability to attract, retain and motivate key personnel until the merger is completed, and could cause customers and others that deal with M&T or People’s United to seek to change existing business relationships with M&T or People’s United. In addition, subject to certain exceptions, People’s United has agreed to operate its business in the ordinary course in all material respects and to refrain from taking certain actions that may adversely affect its ability to consummate the merger on a timely basis without M&T’s consent, and M&T has agreed to refrain from taking certain actions that may adversely affect its ability to consummate the merger on a timely basis without People United’s consent. These restrictions may prevent M&T and/or People’s United from pursuing attractive business opportunities that may arise prior to the completion of the merger. See “The Merger Agreement—Covenants and Agreements” beginning on page 125 for a description of the restrictive covenants applicable to M&T and People’s United.

The merger agreement limits People’s United’s and M&T’s respective abilities to pursue alternatives to the merger and may discourage other companies from trying to acquire People’s United or M&T.

The merger agreement contains “no shop” covenants that restrict each of M&T’s and People’s United’s ability to, directly or indirectly, among other things, initiate, solicit, knowingly encourage or knowingly facilitate, inquiries or proposals with respect to, or, subject to certain exceptions generally related to the exercise of fiduciary duties by each respective board of directors, engage in any negotiations concerning, or provide any confidential or non-public information or data relating to, any alternative acquisition proposals. These provisions, which include a $280 million termination fee payable under certain circumstances, may discourage a potential third-party acquirer that might have an interest in acquiring all or a significant part of People’s United or M&T from considering or proposing that acquisition even if, in the case of a potential acquisition of People’s United, it were prepared to pay consideration with a higher per share price to People’s United stockholders than what is contemplated in the merger, or may result in a potential third-party acquirer proposing to pay a lower per share price to acquire People’s United or M&T than it might otherwise have proposed to pay. For more information, see “The Merger Agreement—Agreement Not to Solicit Other Offers; Termination of the Merger Agreement; Effect of Termination; Termination Fee” and “The Merger Agreement—Meetings; Recommendation of M&T’s and People’s United’s Boards of Directors” beginning on pages 135 and 134 respectively.

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The shares of M&T common stock to be received by People’s United stockholders as a result of the merger will have different rights from the shares of People’s United common stock.

In the merger, People’s United stockholders will become M&T shareholders and their rights as shareholders will be governed by New York law and the governing documents of M&T following the merger. The rights associated with M&T common stock are different from the rights associated with People’s United common stock. See “Comparison of the Rights of M&T Shareholders and People’s United Stockholders” beginning on page 167 for a discussion of the different rights associated with M&T common stock.

M&T and People’s United are expected to incur significant costs related to the merger and integration.

M&T and People’s United have incurred and expect to incur significant, non-recurring costs in connection with negotiating the merger agreement and closing the merger. In addition, M&T will incur integration costs following the completion of the merger as M&T integrates the People’s United business, including facilities and systems consolidation costs and employment-related costs. Anticipated future merger and integration-related pre-tax costs are currently estimated to be approximately $740 million.

There can be no assurances that the expected benefits and efficiencies related to the integration of the businesses will be realized to offset these transaction and integration costs over time. M&T and People’s United may also incur additional costs to maintain employee morale and to retain key employees. M&T and People’s United will also incur significant legal, financial advisory, accounting, banking and consulting fees, fees relating to regulatory filings and notices, SEC filing fees, printing and mailing fees and other costs associated with the merger. Some of these costs are payable regardless of whether the merger is completed. See “The Merger Agreement—Expenses and Fees” beginning on page 139.

General market conditions and unpredictable factors, including conditions and factors different from those affecting People’s United preferred stock currently, could adversely affect market prices for new M&T preferred stock shares once the new M&T preferred stock is issued.

There can be no assurance about the market prices for the new M&T preferred stock that will be issued upon completion of the merger. Several factors, many of which are beyond the control of M&T, could influence the market prices of the new M&T preferred stock, including:

Shares of new M&T preferred stock will be equity interests and will not constitute indebtedness. As such, new M&T preferred stock will rank junior to all indebtedness of, and other non-equity claims on, M&T with respect to assets available to satisfy claims. The market prices for the new M&T preferred stock following the merger may be affected by factors different from those currently affecting the People’s United preferred stock.

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Each current M&T shareholder or People’s United stockholder will have a reduced ownership and voting interest in M&T following the consummation of the merger than the holder’s ownership and voting interest in M&T or People’s United individually, as applicable, prior to the consummation of the merger and will exercise less influence over management.

M&T shareholders and People’s United stockholders currently have the right to vote in the election of the board of directors and on other matters affecting M&T and People’s United, respectively. When the merger is completed, each M&T shareholder and each People’s United stockholder will become an M&T shareholder, with a percentage ownership of M&T that is smaller than the holder’s percentage ownership of either M&T or People’s United individually, as applicable, prior to the consummation of the merger. Based on the number of shares of M&T and People’s United common stock outstanding as of the close of business on the respective record dates, and based on the number of shares of M&T common stock expected to be issued in the merger, the former People’s United stockholders, as a group, are estimated to own approximately twenty-eight percent (28%) of the outstanding shares of M&T immediately after the merger and current M&T shareholders as a group are estimated to own approximately seventy-two percent (72%) of the outstanding shares of M&T immediately after the merger. Because of this, People’s United stockholders may have less influence on the management and policies of M&T than they now have on the management and policies of People’s United, and M&T shareholders may have less influence on the management and policies of M&T when the merger is completed than they now have on the management and policies of M&T.

Issuance of shares of M&T common stock in connection with the merger may adversely affect the market price of M&T common stock.

Based on the number of shares of People’s United common stock outstanding as of April 19, 2021, M&T expects to issue approximately 50.4 million shares of M&T common stock to People’s United stockholders. The issuance of these new shares of M&T common stock may result in fluctuations in the market price of M&T common stock, including a stock price decrease.

M&T shareholders and People’s United stockholders will not have dissenters’ rights or appraisal rights in the merger.

Appraisal rights (also known as dissenters’ rights) are statutory rights that, if applicable under law, enable shareholders to dissent from an extraordinary transaction, such as a merger, and to demand that the corporation pay the fair value for their shares as determined by a court in a judicial proceeding instead of receiving the consideration offered to shareholders in connection with the extraordinary transaction.

Under Section 910 of the NYBCL, M&T shareholders will not be entitled to dissenters’ rights in connection with the merger. If the merger is completed, M&T shareholders will not receive any consideration, and their shares of M&T common stock will remain outstanding and will constitute shares of M&T following the completion of the merger. Accordingly, M&T shareholders are not entitled to any dissenters’ rights in connection with the merger.

Under Section 262 of the DGCL, People’s United stockholders will not be entitled to appraisal rights in connection with the merger if, on the record date of the People’s United special meeting, shares of People’s United’s common stock are listed on a national securities exchange are held of record by more than two thousand (2,000) stockholders, and People’s United stockholders are not required to accept as consideration for their shares anything other than the shares of M&T, shares of another corporation which at the effective date of the merger are either listed on a national securities exchange or held of record by more than two thousand (2,000) stockholders, cash paid in lieu of fractional shares or any combination of the foregoing. People’s United common stock is currently listed on the NASDAQ, a national securities exchange, and is expected to continue to be so listed on the record date for the People’s United special meeting. In addition, People’s United stockholders will receive shares of M&T common stock as consideration in the merger, which shares are currently listed on the NYSE, a national securities exchange, and are expected to continue to be so listed at the effective time. Accordingly, the holders of People’s United common stock are not entitled to any appraisal rights in connection with the merger.

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Litigation related to the merger has been filed against People’s United, the People’s United board of directors and M&T, and additional litigation may be filed against People’s United, the People’s United board of directors, M&T and the M&T board of directors in the future, which could prevent or delay the completion of the merger, result in the payment of damages or otherwise negatively impact the business and operations of M&T and People’s United.

Litigation related to the merger has been filed against People’s United, the People’s United board of directors and M&T, and additional litigation may be filed against People’s United, the People’s United board of directors, M&T and the M&T board of directors in the future. The outcome of any litigation is uncertain. If any plaintiff were successful in obtaining an injunction prohibiting M&T or People’s United from completing the merger, the holdco merger, the bank merger or any of the other transactions contemplated by the merger agreement, then such injunction may delay or prevent the effectiveness of the merger and could result in significant costs to M&T and/or People’s United, including costs in connection with the defense or settlement of any shareholder lawsuits filed in connection with the merger. Further, such lawsuits and the defense or settlement of any such lawsuits may have an adverse effect on the financial condition and results of operations of M&T and People’s United.

The COVID-19 pandemic’s impact on M&T’s business and operations following the completion of the merger is uncertain.

The extent to which the COVID-19 pandemic will negatively affect the business, financial condition, liquidity, capital and results of operations of M&T following the completion of the merger will depend on future developments, which are highly uncertain and cannot be predicted, including the scope and duration of the COVID-19 pandemic, the direct and indirect impact of the COVID-19 pandemic on employees, clients, counterparties and service providers, as well as other market participants, and actions taken by governmental authorities and other third parties in response to the COVID-19 pandemic. Given the ongoing and dynamic nature of the circumstances, it is difficult to predict the impact of the COVID-19 pandemic on M&T’s business, and there is no guarantee that efforts by M&T to address the adverse impacts of the COVID-19 pandemic will be effective.

Even after the COVID-19 pandemic has subsided, M&T may continue to experience adverse impacts to its business as a result of the COVID-19 pandemic’s global economic impact, including reduced availability of credit, adverse impacts on liquidity and the negative financial effects from any recession or depression that may occur.

Risks Relating to M&T’s Business

You should read and consider risk factors specific to M&T’s business (including those related to the COVID-19 pandemic) that will also affect M&T after the merger. These risks are described in the sections entitled “Risk Factors” in M&T’s Annual Report on Form 10-K for the year ended December 31, 2020 and in other documents incorporated by reference into this joint proxy statement/prospectus. Please see the section entitled “Where You Can Find More Information” beginning on page 185 of this joint proxy statement/prospectus for the location of information incorporated by reference into this joint proxy statement/prospectus.

Risks Relating to People’s United’s Business

You should read and consider risk factors specific to People’s United’s business (including those related to the COVID-19 pandemic) that will also affect M&T following the completion of the merger. These risks are described in the sections entitled “Risk Factors” in People’s United’s Annual Report on Form 10-K for the year ended December 31, 2020 and in other documents incorporated by reference into this joint proxy statement/prospectus. Please see the section entitled “Where You Can Find More Information” beginning on page 185 of this joint proxy statement/prospectus for the location of information incorporated by reference into this joint proxy statement/prospectus.

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THE M&T SPECIAL MEETING

This section contains information for M&T shareholders about the special meeting that M&T has called to allow M&T shareholders to consider and vote on the M&T charter amendment proposal, the M&T share issuance proposal and other related matters. This joint proxy statement/prospectus is accompanied by a notice of the M&T special meeting, and a form of proxy card that the M&T board of directors is soliciting for use by M&T shareholders at the special meeting and at any adjournments or postponements of the special meeting.

Date, Time and Place of the Meeting

The M&T special meeting will be held virtually via the internet on May 25, 2021 at 11:00 A.M, Eastern Time. Due to the continuing public health impact of the COVID-19 pandemic and to support the well-being of our shareholders and employees, the M&T special meeting will be held in a virtual meeting format conducted via webcast.

Matters to Be Considered

At the M&T special meeting, M&T shareholders will be asked to consider and vote upon the following proposals:

Recommendation of M&T’s Board of Directors

The M&T board of directors recommends that you vote “FOR” the M&T charter amendment proposal, “FOR” the M&T share issuance proposal and “FOR” the M&T adjournment proposal. See “The Merger—M&T’s Reasons for the Merger; Recommendation of M&T’s Board of Directors” beginning on page 64 for a more detailed discussion of the M&T board of directors’ recommendation.

Record Date and Quorum

The M&T board of directors has fixed the close of business on April 19, 2021 as the record date for the determination of holders of M&T common stock entitled to notice of and to vote at the M&T special meeting. As of the M&T record date, there were 128,645,421 shares of M&T common stock outstanding.

Holders of a majority of the shares of M&T common stock outstanding on the record date must be present, either in attendance virtually via the M&T special meeting website or by proxy, to constitute a quorum at the M&T special meeting. If you fail to submit a proxy prior to the special meeting or to vote at the M&T special meeting via the M&T special meeting website, your shares of M&T common stock will not be counted towards a quorum. Abstentions are considered present for purposes of establishing a quorum.

At the M&T special meeting, each share of M&T common stock is entitled to one (1) vote on all matters properly submitted to M&T shareholders.

As of the close of business on the M&T record date, M&T directors and executive officers and their affiliates owned and were entitled to vote approximately 645,474 shares of M&T common stock, representing less than one percent (1%) of the outstanding shares of M&T common stock. We currently expect that M&T’s directors and executive officers will vote their shares in favor of the M&T charter amendment proposal, the M&T share issuance proposal and the M&T adjournment proposal, although none of them has entered into any agreements obligating them to do so.

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Vote Required; Treatment of Abstentions and Failure to Vote

M&T charter amendment proposal:

M&T share issuance proposal:

M&T adjournment proposal:

Holders of M&T preferred stock are not entitled to and are not requested to vote at the M&T special meeting.

Attending the Virtual Special Meeting

The M&T special meeting may be accessed via the M&T special meeting website, where M&T shareholders will be able to listen to the M&T special meeting, submit questions and vote online. You are entitled to attend the M&T special meeting via the M&T special meeting website only if you were a shareholder of record at the close of business on the record date (a “record holder”) or you held your M&T shares beneficially in the name of a bank, broker, trustee or other nominee as of the record date (a “beneficial owner”), or you hold a valid proxy for the M&T special meeting.

If you are a record holder you will be able to attend the M&T special meeting online, ask questions and vote during the meeting by visiting www.meetingcenter.io/255180428 and following the instructions. Please have your control number, which can be found on your proxy card, notice or email previously received, to access the meeting. If you are a beneficial owner, you also will be able to attend the M&T special meeting online, ask questions and vote during the meeting by visiting www.meetingcenter.io/255180428 and following the instructions. Please have your control number, which can be found on your proxy card, notice or email

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previously received, to access the meeting. Please review this information prior to the M&T special meeting to ensure you have access.

See “—Shares Held in Street Name” below for further information.

Shareholders will have substantially the same opportunities to participate in the virtual M&T special meeting as they would have at a physical, in-person meeting. Shareholders as of the record date will be able to attend, vote, examine the shareholder list, and submit questions during a portion of the meeting via the online platform. To ensure the M&T special meeting is conducted in a manner that is fair to all shareholders, we may exercise discretion in determining the order in which questions are answered and the amount of time devoted to any one question. We reserve the right to edit or reject questions we deem inappropriate or not relevant to the M&T special meeting’s limited purpose.

Technical assistance will be available for shareholders who experience an issue accessing the M&T special meeting. Contact information for technical support will appear on the M&T special meeting website prior to the start of the M&T special meeting.

Proxies

A holder of M&T common stock may vote by proxy or at the M&T special meeting via the M&T special meeting website. If you hold your shares of M&T common stock in your name as a record holder, to submit a proxy, you, as a holder of M&T common stock, may use one of the following methods:

M&T requests that M&T shareholders vote by telephone, over the internet or by completing and signing the accompanying proxy card and returning it to M&T as soon as possible in the enclosed postage-paid envelope. When the accompanying proxy card is returned properly executed, the shares of M&T common stock represented by it will be voted at the M&T special meeting in accordance with the instructions contained on the proxy card. If you make no specification on your proxy card as to how you want your shares voted before signing and returning it, your proxy will be voted “FOR” the M&T charter amendment proposal, “FOR” the M&T share issuance proposal and “FOR” the M&T adjournment proposal.

If you are a beneficial owner, the holder should check the voting form used by that firm to determine whether the holder may vote by telephone or the internet.

Every vote is important. Accordingly, you should sign, date and return the enclosed proxy card, or vote via the internet or by telephone, whether or not you plan to attend the M&T special meeting virtually via the M&T special meeting website. Sending in your proxy card or voting by telephone or on the internet will not prevent you from voting your shares personally via the M&T special meeting website at the meeting because you may revoke your proxy at any time before it is voted.

Shares Held in Street Name

If your shares are held in “street name” through a broker, bank, trustee or other nominee, you must instruct the broker, bank, trustee or other nominee on how to vote your shares. Your broker, bank, trustee or other nominee will vote your shares only if you provide specific instructions on how to vote by following the instructions provided to you by your broker, bank, trustee or other nominee.

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Further, brokers, banks, trustees or other nominees who hold shares of M&T common stock on behalf of their customers may not give a proxy to M&T to vote those shares with respect to any of the proposals without specific instructions from their customers, as brokers, banks, trustees and other nominees do not have discretionary voting power on the proposals that will be voted upon at the M&T special meeting, including the M&T charter amendment proposal, the M&T share issuance proposal, and the M&T adjournment proposal.

Revocability of Proxies

If you directly hold shares of M&T common stock in your name as a record holder, you can change your vote at any time before your proxy is voted at your meeting. You can do this by:

If your shares are held by a broker, bank, trustee or other nominee, you should contact your broker, bank, trustee or other nominee to change your vote.

Attendance virtually at the M&T special meeting will not in and of itself constitute revocation of a proxy. A revocation or later-dated proxy received by M&T after the vote will not affect the vote. M&T’s corporate secretary’s mailing address is: One M&T Plaza, Buffalo, New York 14203. If the M&T virtual special meeting is postponed or adjourned, it will not affect the ability of M&T shareholders of record as of the record date to exercise their voting rights or to revoke any previously granted proxy using the methods described above.

Delivery of Proxy Materials

As permitted by applicable law, only one copy of this joint proxy statement/prospectus is being delivered to M&T shareholders residing at the same address, unless such M&T shareholders have notified M&T of their desire to receive multiple copies of the joint proxy statement/prospectus.

M&T will promptly deliver, upon oral or written request, a separate copy of the joint proxy statement/prospectus to any M&T shareholder residing at an address to which only one copy of such document was mailed. Requests for additional copies should be directed M&T’s proxy solicitor, Georgeson, by calling toll-free at 1-866-856-4733.

Solicitation of Proxies

M&T and People’s United will share equally the expenses incurred in connection with the printing and mailing of this joint proxy statement/prospectus. To assist in the solicitation of proxies, M&T has retained Georgeson, and will pay Georgeson a fee of $15,000 plus reasonable expenses for these services. M&T and its proxy solicitor may also request banks, brokers, trustees and other intermediaries holding shares of M&T common stock beneficially owned by others to send this document to, and obtain proxies from, the beneficial owners and may reimburse such record holders for their reasonable out-of-pocket expenses in so doing. Solicitation of proxies by mail may be supplemented by telephone and other electronic means, advertisements and personal solicitation by the directors, officers or employees of M&T. No additional compensation will be paid to our directors, officers or employees for solicitation.

Other Matters to Come Before the M&T Special Meeting

M&T management knows of no other business to be presented at the M&T special meeting, but if any other matters are properly presented to the meeting or any adjournments thereof, the persons named in the proxies will vote upon them in accordance with the M&T board of directors’ recommendations.

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Assistance

If you need assistance in completing your proxy card, have questions regarding M&T’s special meeting or would like additional copies of this joint proxy statement/prospectus, please contact Shareholder Relations, M&T, One M&T Plaza, Buffalo, New York 14203, telephone 716-842-5138, e-mail ir@mtb.com, or M&T’s proxy solicitor, Georgeson, at the following address or phone number: 1290 Avenue of the Americas, 9th Floor

New York, NY 10104, or calling toll-free: 1-866-856-4733.

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M&T PROPOSALS

PROPOSAL 1: M&T CHARTER AMENDMENT PROPOSAL

Pursuant to the merger agreement, M&T is asking the M&T shareholders to approve an amendment to the M&T certificate of incorporation to effect an increase in the number of authorized shares of M&T capital stock from 251,000,000 to 270,000,000 and to effect an increase in the number of authorized shares of M&T’s preferred stock from 1,000,000 to 20,000,000, to be effective only upon the completion of the merger. A copy of the proposed certificate of amendment to the M&T certificate of incorporation is attached to this joint proxy statement/prospectus as Annex B. M&T shareholders should read the proposed certificate of amendment to the M&T certificate of incorporation in its entirety. The approval of the M&T charter amendment proposal by M&T shareholders is a condition to the completion of the merger.

After careful consideration, the M&T board of directors determined that the merger agreement and the transactions contemplated by the merger agreement are advisable and in the best interests of M&T and its shareholders and unanimously adopted and approved the merger agreement, the mergers and the other transactions contemplated by the merger agreement. See “The Merger— M&T’s Reasons for the Merger; Recommendation of M&T Board of Directors” beginning on page 64 for a more detailed discussion of the M&T board of directors’ recommendation.

The M&T board of directors unanimously recommends a vote “FOR” the M&T charter amendment proposal.

PROPOSAL 2: M&T SHARE ISSUANCE PROPOSAL

Pursuant to the merger agreement, M&T is asking M&T shareholders to approve the issuance of M&T common stock to People’s United stockholders. M&T shareholders should read this joint proxy statement/prospectus carefully and in its entirety, including the annexes, for more detailed information concerning the merger agreement and the mergers. A copy of the merger agreement is attached to this joint proxy statement/prospectus as Annex A.

After careful consideration, the M&T board of directors determined that the merger agreement and the transactions contemplated by the merger agreement are advisable and in the best interests of M&T and its shareholders and unanimously adopted and approved the merger agreement, the mergers and the other transactions contemplated by the merger agreement. See “The Merger— M&T’s Reasons for the Merger; Recommendation of the M&T Board of Directors” beginning on page 64 for a more detailed discussion of the M&T board of directors’ recommendation.

The M&T board of directors unanimously recommends a vote “FOR” the M&T share issuance proposal.

PROPOSAL 3: M&T ADJOURNMENT PROPOSAL

The M&T special meeting may be adjourned to another time or place, if necessary or appropriate, to solicit additional proxies if there are insufficient votes at the time of the M&T special meeting to approve the M&T charter amendment proposal, the M&T share issuance proposal or to ensure that any supplement or amendment to this joint proxy statement/prospectus is timely provided to M&T shareholders. If, at the M&T special meeting, the number of shares of M&T common stock present or represented and voting in favor of M&T charter amendment proposal and/or the M&T share issuance proposal is insufficient to approve the M&T charter amendment proposal and/or the M&T share issuance proposal, as the case may be, M&T intends to move to adjourn the M&T special meeting in order to enable the M&T board of directors to solicit additional proxies for approval of the M&T charter amendment proposal and/or the M&T share issuance proposal, as the case may be. In that event, M&T will ask M&T shareholders to vote upon the M&T adjournment proposal, but not the M&T charter amendment proposal or the M&T share issuance proposal.

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In this proposal, M&T is asking M&T shareholders to authorize the holder of any proxy solicited by the M&T board of directors, on a discretionary basis, if a quorum is not present, and (i) if there are not sufficient votes at the time of the M&T special meeting to approve the M&T charter amendment proposal and/or the M&T share issuance proposal or (ii) if necessary or appropriate to ensure that any supplement or amendment to this joint proxy statement/prospectus is timely provided to M&T shareholders, to vote in favor of adjourning the M&T special meeting to another time and place for the purpose of soliciting additional proxies, including the solicitation of proxies from M&T shareholders who have previously voted. Pursuant to the M&T bylaws, the M&T special meeting may be adjourned without new notice being given.

The approval of the M&T adjournment proposal by M&T shareholders is not a condition to the completion of the merger.

The M&T board of directors unanimously recommends a vote “FOR” the M&T adjournment proposal.

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THE PEOPLE’S UNITED SPECIAL MEETING

This section contains information for People’s United stockholders about the special meeting that People’s United has called to allow People’s United stockholders to consider and vote on the People’s United merger proposal and other related matters. This joint proxy statement/prospectus is accompanied by a notice of the People’s United special meeting, and a form of proxy card that the People’s United board of directors is soliciting for use by People’s United stockholders at the special meeting and at any adjournments or postponements of the special meeting.

Date, Time and Place of the Meeting

The People’s United special meeting will be held virtually via the internet on May 25, 2021 at 11:00 A.M., Eastern Time. In light of the ongoing developments related to the COVID-19 pandemic and to support the health and safety of our stockholders, employees and community, the People’s United special meeting will be held in a virtual-only format conducted via live webcast.

Matters to Be Considered

At the People’s United special meeting, People’s United stockholders will be asked to consider and vote upon the following proposals:

Recommendation of People’s United’s Board of Directors

The People’s United board of directors recommends that you vote “FOR” the People’s United merger proposal, “FOR” the People’s United compensation proposal and “FOR” the People’s United adjournment proposal. See “The Merger—People’s United’s Reasons for the Merger; Recommendation of People’s United’s Board of Directors” beginning on page  75 for a more detailed discussion of the People’s United board of directors’ recommendation.

Record Date and Quorum

The People’s United stockholders’ meeting committee of the board of directors has fixed the close of business on April 19, 2021 as the record date for determination of People’s United stockholders entitled to notice of and to vote at the People’s United special meeting. As of the record date, there were 427,394,600 shares of People’s United common stock outstanding.

Holders of a majority of the outstanding shares of People’s United common stock entitled to vote at the People’s United special meeting must be present, either in attendance virtually via the People’s United special meeting website or by proxy, to constitute a quorum at the People’s United special meeting. If you fail to submit a proxy prior to the special meeting, or to vote at the People’s United special meeting via the People’s United special meeting website, your shares of People’s United common stock will not be counted towards a quorum. Abstentions are considered present for the purpose of establishing a quorum but will not be counted as shares present and entitled to vote at the meeting.

At the People’s United special meeting, each share of People’s United common stock is entitled to one (1) vote on all matters properly submitted to People’s United stockholders.

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As of the close of business on the People’s United record date, People’s United directors and executive officers and their affiliates owned and were entitled to vote approximately 3,522,500 shares of People’s United common stock, representing less than one percent (1%) of the outstanding shares of People’s United common stock. We currently expect that People’s United’s directors and executive officers will vote their shares in favor of the People’s United merger proposal, the People’s United compensation proposal and the People’s United adjournment proposal, although none of them has entered into any agreements obligating them to do so.

Vote Required; Treatment of Abstentions and Failure to Vote

People’s United merger proposal:

People’s United compensation proposal:

People’s United adjournment proposal:

Holders of People’s United preferred stock are not entitled to and are not requested to vote at the People’s United special meeting.

Attending the Virtual Special Meeting

The People’s United special meeting may be accessed via the People’s United special meeting website, where People’s United stockholders will be able to listen to the People’s United special meeting, submit questions and vote online. You are entitled to attend the People’s United special meeting via the People’s United special meeting website only if you were a stockholder of record at the close of business on the record date (a “record

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holder”) or you held your People’s United shares beneficially in the name of a bank, broker, trustee or other nominee as of the record date (a “beneficial owner”), or you hold a valid proxy for the People’s United special meeting.

If you are a record holder you will be able to attend the People’s United special meeting online, ask questions and vote during the meeting by visiting www.virtualshareholdermeeting.com/PBCT2021SM and following the instructions. Please have your 16-digit control number, which can be found on your proxy card, notice or email previously received, to access the meeting. If you are a beneficial owner, you also will be able to attend the People’s United special meeting online, ask questions and vote during the meeting by visiting www.virtualshareholdermeeting.com/PBCT2021SM and following the instructions. Please have your 16-digit control number, which can be found on the voting instructions provided by your bank, broker, trustee or other nominee, to access the meeting. Please review this information prior to the People’s United special meeting to ensure you have access.

See “—Shares Held in Street Name” below for further information.

Stockholders will have substantially the same opportunities to participate in the virtual People’s United special meeting as they would have at a physical, in-person meeting. Stockholders as of the record date will be able to attend, vote, examine the stockholder list, and submit questions during a portion of the meeting via the online platform. To ensure the People’s United special meeting is conducted in a manner that is fair to all stockholders, we may exercise discretion in determining the order in which questions are answered and the amount of time devoted to any one question. We reserve the right to edit or reject questions we deem inappropriate or not relevant to the People’s United special meeting’s limited purpose.

Technical assistance will be available for stockholders who experience an issue accessing the People’s United special meeting. Contact information for technical support will appear on the People’s United special meeting website starting fifteen (15) minutes prior to the start of the People’s United special meeting.

Proxies

A holder of People’s United shares may vote by proxy or at the People’s United special meeting via the People’s United special meeting website. If you hold your shares of People’s United common stock in your name as a record holder, to submit a proxy, you, as a holder of People’s United common stock, may use one of the following methods:

People’s United requests that People’s United stockholders vote by telephone, over the internet or by completing and signing the accompanying proxy card and returning it to People’s United as soon as possible in the enclosed postage-paid envelope. When the accompanying proxy card is returned properly executed, the shares of People’s United common stock represented by it will be voted at the People’s United special meeting in accordance with the instructions contained on the proxy card. If you make no specification on your proxy card as to how you want your shares voted before signing and returning it, your proxy will be voted “FOR” the People’s United merger proposal, “FOR” the People’s United compensation proposal and “FOR” the People’s United adjournment proposal.

If you are a beneficial owner, you should check the voting form used by that firm to determine whether you may vote by telephone or the internet.

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Every vote is important. Accordingly, you should sign, date and return the enclosed proxy card, or vote via the internet or by telephone, whether or not you plan to attend the People’s United special meeting virtually via the People’s United special meeting website. Sending in your proxy card or voting by telephone or on the internet will not prevent you from voting your shares personally via the People’s United special meeting website at the meeting because you may revoke your proxy at any time before it is voted.

Shares Held in Street Name

If you are a beneficial owner, you will be able to attend the People’s United special meeting online, ask questions and vote during the meeting by visiting www.virtualshareholdermeeting.com/PBCT2021SM and following the instructions. Please have your 16-digit control number, which can be found on the voting instructions provided by your bank, broker, trustee or other nominee, to access the meeting. Please contact your bank, broker, trustee or other nominee to obtain further instructions.

If you do not attend the People’s United special meeting and wish to vote, you must instruct the bank, broker, trustee or other nominee on how to vote your shares. Your bank, broker, trustee or other nominee will vote your shares only if you provide specific instructions on how to vote by following the instructions provided to you by your bank, broker, trustee or other nominee.

Further, banks, brokers, trustees or other nominees who hold shares on behalf of their customers may not give a proxy to People’s United to vote those shares with respect to any of the proposals without specific instructions from their customers, as banks, brokers, trustees and other nominees do not have discretionary voting power on the proposals that will be voted upon at the People’s United special meeting, including the People’s United merger proposal, the People’s United compensation proposal and the People’s United adjournment proposal.

Revocability of Proxies

If you directly hold shares of People’s United common stock in your name as a record holder, you can change your proxy vote at any time before your proxy is voted at the People’s United special meeting. You can do this by:

If you are a beneficial owner of People’s United common stock, you may change your vote by:

Attendance virtually at the People’s United special meeting will not in and of itself constitute revocation of a proxy. A revocation or later-dated proxy received by People’s United after the vote will not affect the vote. People’s United’s corporate secretary’s mailing address is: 850 Main Street, Bridgeport, Connecticut 06604. If the People’s United virtual special meeting is postponed or adjourned, it will not affect the ability of People’s United stockholders of record as of the record date to exercise their voting rights or to revoke any previously granted proxy using the methods described above.

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Delivery of Proxy Materials

As permitted by applicable law, only one copy of this joint proxy statement/prospectus is being delivered to People’s United stockholders residing at the same address, unless such People’s United stockholders have notified People’s United of their desire to receive multiple copies of the joint proxy statement/prospectus.

People’s United will promptly deliver, upon oral or written request, a separate copy of the joint proxy statement/prospectus to any holder of People’s United common stock residing at an address to which only one copy of such document was mailed. Requests for additional copies should be directed to People’s United’s proxy solicitor, D.F. King & Co., Inc. by calling toll-free at (800) 207-3159.

Solicitation of Proxies

People’s United and M&T will share equally the expenses incurred in connection with the printing and mailing of this joint proxy statement/prospectus. To assist in the solicitation of proxies, People’s United has retained D.F. King & Co., Inc., for a fee of $20,000 plus reimbursement of certain costs and expenses incurred in connection with the solicitation. People’s United and its proxy solicitor will also request banks, brokers, trustees and other intermediaries holding shares of People’s United common stock beneficially owned by others to send this document to, and obtain proxies from, the beneficial owners and may reimburse such record holders for their reasonable out-of-pocket expenses in so doing. Solicitation of proxies by mail may be supplemented by telephone and other electronic means, advertisements and personal solicitation by the directors, officers or employees of People’s United. No additional compensation will be paid to People’s United’s directors, officers or employees for solicitation.

You should not send in any People’s United stock certificates with your proxy card (or, if you are a beneficial owner, your voting instruction card). The exchange agent will mail a transmittal letter with instructions for the surrender of stock certificates to People’s United stockholders as soon as practicable after completion of the merger.

Other Matters to Come Before the People’s United Special Meeting

People’s United management knows of no other business to be presented at the People’s United special meeting, but if any other matters are properly presented to the meeting or any adjournments thereof, the persons named in the proxies will vote upon them in accordance with the People’s United board of directors’ recommendations.

Assistance

If you need assistance in completing your proxy card, have questions regarding People’s United’s special meeting or would like additional copies of this joint proxy statement/prospectus, please contact Investor Relations, People’s United, 850 Main Street, Bridgeport, Connecticut 06604, telephone (203) 338-4851, or People’s United’s proxy solicitor, D.F. King & Co., Inc., by calling toll-free: (800) 207-3159.

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PEOPLE’S UNITED PROPOSALS

PROPOSAL 1: PEOPLE’S UNITED MERGER PROPOSAL

Pursuant to the merger agreement, People’s United is asking People’s United stockholders to approve the adoption of the merger agreement and the transactions contemplated thereby, including the merger. People’s United stockholders should read this joint proxy statement/prospectus carefully and in its entirety, including the annexes, for more detailed information concerning the merger agreement and the merger. A copy of the merger agreement is attached to this joint proxy statement/prospectus as Annex A.

After careful consideration, the People’s United board of directors, by a unanimous vote of all directors, approved the merger agreement and declared the merger agreement and the transactions contemplated thereby, including the merger, to be advisable and in the best interest of People’s United and People’s United stockholders. See “The Merger—People’s United’s Reasons for the Merger; Recommendation of People’s United’s Board of Directors” beginning on page 75 for a more detailed discussion of the People’s United board of directors’ recommendation.

The approval of the People’s United merger proposal by People’s United stockholders is a condition to the completion of the merger.

The People’s United board of directors unanimously recommends a vote “FOR” the People’s United merger proposal.

PROPOSAL 2: PEOPLE’S UNITED COMPENSATION PROPOSAL

Pursuant to Section 14A of the Exchange Act and Rule 14a-21(c) thereunder, People’s United is seeking a non-binding, advisory stockholder approval of the compensation of People’s United’s named executive officers that is based on or otherwise relates to the merger as disclosed in the section entitled “The Merger—Interests of Certain People’s United Directors and Executive Officers in the Merger—Quantification of Potential Payments and Benefits to People’s United’s Named Executive Officers in Connection with the Merger—Golden Parachute Compensation” beginning on page 110. The proposal gives People’s United stockholders the opportunity to express their views on the merger-related compensation of People’s United’s named executive officers.

Accordingly, People’s United is asking People’s United stockholders to vote “FOR” the adoption of the following resolution, on a non-binding advisory basis:

“RESOLVED, that the compensation that will or may be paid or become payable to the People’s United named executive officers, in connection with the merger, and the agreements or understandings pursuant to which such compensation will or may be paid or become payable, in each case as disclosed pursuant to Item 402(t) of Regulation S-K in “Interests of Certain People’s United Directors and Executive Officers in the Merger—Quantification of Potential Payments and Benefits to People’s United’s Named Executive Officers in Connection with the Merger—Golden Parachute Compensation,” are hereby APPROVED.”

The advisory vote on the People’s United compensation proposal is a vote separate and apart from the votes on the People’s United merger proposal and the People’s United adjournment proposal. Accordingly, if you are a holder of People’s United common stock, you may vote to approve the People’s United merger proposal and/or the People’s United adjournment proposal and vote not to approve the People’s United compensation proposal, and vice versa. The approval of the People’s United compensation proposal by People’s United stockholders is not a condition to the completion of the merger. If the merger is completed, the merger-related compensation will be paid to People’s United’s named executive officers to the extent payable in accordance with the terms of the compensation agreements and arrangements even if People’s United stockholders fail to approve the advisory vote regarding merger-related compensation.

The People’s United board of directors unanimously recommends a vote “FOR” the advisory People’s United compensation proposal.

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PROPOSAL 3: PEOPLE’S UNITED ADJOURNMENT PROPOSAL

The People’s United special meeting may be adjourned to another time or place, if necessary or appropriate, to solicit additional proxies if there are insufficient votes at the time of the People’s United special meeting to approve the People’s United merger proposal or to ensure that any supplement or amendment to this joint proxy statement/prospectus is timely provided to People’s United stockholders.

If, at the People’s United special meeting, the number of shares of People’s United common stock present or represented and voting in favor of the People’s United merger proposal is insufficient to approve the People’s United merger proposal, People’s United intends to move to adjourn the People’s United special meeting in order to enable the People’s United board of directors to solicit additional proxies for approval of the People’s United merger proposal. In that event, People’s United will ask People’s United stockholders to vote upon the People’s United adjournment proposal, but not the People’s United merger proposal or the People’s United compensation proposal.

In this proposal, People’s United is asking People’s United stockholders to authorize the holder of any proxy solicited by the People’s United board of directors on a discretionary basis (i) if there are not sufficient votes at the time of the People’s United special meeting to approve the People’s United merger proposal or (ii) if necessary or appropriate to ensure that any supplement or amendment to this joint proxy statement/prospectus is timely provided to People’s United stockholders, to vote in favor of adjourning the People’s United special meeting to another time and place for the purpose of soliciting additional proxies, including the solicitation of proxies from People’s United stockholders who have previously voted. Pursuant to the People’s United bylaws, the People’s United special meeting may be adjourned without new notice being given unless the adjournment is for more than thirty (30) days or if a new record date is set for the adjourned meeting.

The approval of the People’s United adjournment proposal by People’s United stockholders is not a condition to the completion of the merger.

The People’s United board of directors unanimously recommends a vote “FOR” the People’s United adjournment proposal.

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INFORMATION ABOUT THE COMPANIES

M&T Bank Corporation

M&T is a New York business corporation which is registered as a financial holding company under the BHC Act, and as a bank holding company under Article III-A of the New York Banking Law. M&T was incorporated in November 1969. As of December 31, 2020, M&T had consolidated total assets of $142.6 billion, deposits of $119.8 billion and shareholders’ equity of $16.2 billion. M&T had 16,718 full-time and 655 part-time employees as of December 31, 2020.

At December 31, 2020, M&T had two wholly owned bank subsidiaries: M&T Bank and Wilmington Trust, National Association. The banks collectively offer a wide range of retail and commercial banking, trust and wealth management, and investment services to their customers. At December 31, 2020, M&T Bank represented ninety-nine percent (99%) of consolidated assets of M&T, and had 716 domestic banking offices located in New York, Maryland, New Jersey, Pennsylvania, Delaware, Connecticut, Virginia, West Virginia and the District of Columbia, a full-service commercial banking office in Ontario, Canada, and an office in George Town, Cayman Islands. As a commercial bank, M&T Bank offers a broad range of financial services to a diverse base of consumers, businesses, professional clients, governmental entities and financial institutions located in its markets.

M&T’s common stock is traded on the NYSE under the symbol “MTB.” The principal executive offices of M&T are located at One M&T Plaza, Buffalo, New York 14203, and its telephone number is (716) 635-4000.

People’s United

People’s United is a bank holding company and a financial holding company registered under the BHC Act, and is incorporated under the state laws of Delaware. People’s United is the holding company for People’s United Bank, National Association (“People’s United Bank”), a national banking association headquartered in Bridgeport, Connecticut. As of December 31, 2020, People’s United had consolidated total assets of $63.1 billion, deposits of $52.1 billion and stockholders’ equity of $7.6 billion. People’s United had 5,640 full-time, 287 part-time and 60 temporary employees as of December 31, 2020.

The principal business of People’s United is to provide, through People’s United Bank and its subsidiaries, commercial banking, retail banking and wealth management services to individual, corporate and municipal customers. Traditional banking activities are conducted primarily within New England and southeastern New York, and include extending secured and unsecured commercial and consumer loans, originating mortgage loans secured by residential and commercial properties, and accepting consumer, commercial and municipal deposits.

In addition to traditional banking activities, People’s United Bank provides specialized financial services tailored to specific markets including: personal, institutional and employee benefit trust; cash management; and municipal banking. Through its non-banking subsidiaries, People’s United Bank offers: equipment financing through People’s Capital and Leasing Corp., People’s United Equipment Finance Corp. and LEAF Commercial Capital, Inc.; brokerage, financial advisory services, investment management services and life insurance through People’s Securities, Inc.; and investment advisory services and financial management and planning services through People’s United Advisors, Inc.

People’s United’s common stock is traded on the NASDAQ Global Select Market under the symbol “PBCT.” The principal executive offices of People’s United are located at 850 Main Street, Bridgeport, Connecticut 06604, and its telephone number is (203) 338-7171.

Merger Sub

Merger Sub, a direct, wholly owned subsidiary of M&T, is a Delaware corporation that was incorporated for the sole purpose of effecting the merger. In the merger, Merger Sub will merge with and into People’s United, with

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People’s United surviving as a direct, wholly owned subsidiary of M&T and the separate corporate existence of Merger Sub will cease.

Its principal executive office is located at c/o M&T Bank Corporation, One M&T Plaza, Buffalo, New York 14203, and its telephone number is (716) 635-4000.

Recent Developments

M&T Preliminary 2021 First Quarter Financial Results

On April 19, 2021, M&T announced its unaudited preliminary financial results for the quarter ended March 31, 2021. The preliminary financial data included in this joint proxy statement/prospectus has been prepared by, and is the responsibility of, M&T’s management. PricewaterhouseCoopers LLP has not audited, reviewed, compiled, or applied agreed-upon procedures with respect to the preliminary financial data. Accordingly, PricewaterhouseCoopers LLP does not express an opinion or any other form of assurance with respect thereto.

Diluted earnings per common share measured in accordance with GAAP were $3.33 in the first quarter of 2021, compared with $1.93 in the year-earlier quarter and $3.52 in the fourth quarter of 2020. GAAP basis net income was $447 million in the recent quarter, $269 million in the first quarter of 2020 and $471 million in the final 2020 quarter. GAAP-basis net income in the initial 2021 quarter expressed as an annualized rate of return on average assets and average common shareholders’ equity was 1.22% and 11.57%, respectively, compared with .90% and 7.00%, respectively, in the corresponding 2020 period and 1.30% and 12.07%, respectively, in the fourth quarter of 2020. Included in noninterest expenses in the recent quarter were merger-related expenses associated with M&T’s proposed acquisition of People’s United of $10 million ($8 million after tax-effect, or $.06 of diluted earnings per common share).

M&T recorded a provision for credit losses recapture of $25 million in the first quarter of 2021, compared with provisions of $250 million in the year-earlier quarter and $75 million in 2020’s fourth quarter. The provision recapture reflects improvements in macroeconomic forecasts at March 31, 2021 as compared with previous forecasts. Nevertheless, the impact of those improvements was cautiously evaluated given the somewhat uneven and incomplete recovery evident in the economy through the recent quarter-end. The level of the provisions in the 2020 quarters reflected then projections of expected credit losses that were based on economic forecasts at those times. Net loan charge-offs were $75 million during the recent quarter, compared with $49 million in the first quarter of 2020 and $97 million in the fourth quarter of 2020. Expressed as an annualized percentage of average loans outstanding, net charge-offs were .31% and .22% in the first quarters of 2021 and 2020, respectively, and .39% in the fourth quarter of 2020.

Loans classified as nonaccrual totaled $1.96 billion or 1.97% of total loans outstanding at March 31, 2021, compared with $1.89 billion or 1.92% of total loans at December 31, 2020 and $1.06 billion or 1.13% at March 31, 2020. The increase in nonaccrual loans from March 31, 2020 to the two most recent quarter-ends reflects the continuing impact of the pandemic on borrowers’ ability to make contractual payments on their loans, most notably loans in the hospitality sector. Assets taken in foreclosure of defaulted loans were $30 million at March 31, 2021, $84 million a year earlier and $35 million at December 31, 2020.

M&T had total assets of $150.5 billion at March 31, 2021, compared with $124.6 billion and $142.6 billion at March 31, 2020 and December 31, 2020, respectively. Loans and leases, net of unearned discount, were $99.3 billion at March 31, 2021, up from $94.1 billion at March 31, 2020 and $98.5 billion at December 31, 2020. Total deposits rose to $128.5 billion at the recent quarter-end, compared with $100.2 billion at March 31, 2020 and $119.8 billion at December 31, 2020. Total shareholders’ equity was $16.4 billion, or 10.93% of total assets at March 31, 2021, $15.8 billion, or 12.70% at March 31, 2020 and $16.2 billion, or 11.35% at December 31, 2020.

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The foregoing is only a summary and is not intended to be a comprehensive statement of M&T’s unaudited preliminary financial results. Interim financial statements as of and for the period ended March 31, 2021 will be included in M&T’s Quarterly Report on Form 10-Q to be filed by M&T with the SEC.

People’s United Preliminary 2021 First Quarter Financial Results

On April 22, 2021, People’s United announced its unaudited preliminary financial results for the quarter ended March 31, 2021. The preliminary financial data included in this joint proxy statement/prospectus has been prepared by, and is the responsibility of, People’s United’s management. KPMG LLP has not audited, reviewed, compiled, or applied agreed-upon procedures with respect to the preliminary financial data. Accordingly, KPMG LLP does not express an opinion or any other form of assurance with respect thereto.

Net Income totaled $144.5 million, or $0.33 per common share for the first quarter of 2021. Net interest margin of 2.74 percent was 10 basis points lower than the fourth quarter due to lower yields in the securities portfolio, two fewer calendars days and increased excess liquidity. These headwinds were partially offset by a further reduction in deposits costs for the seventh consecutive quarter, and stable loan yields. The loan-to-deposit ratio concluded the quarter at 80 percent as loans decreased $1.1 billion or three percent from December 31, while deposits grew $1.3 billion or three percent. The decline in period-end loans was largely driven by $586 million in lower retail balances, and a $431 million reduction in mortgage warehouse from a record level at year-end. Conversely, the loan portfolio benefited from a net increase in PPP balances of $288 million and continued solid results in LEAF. Deposit growth reflected federal stimulus payments, PPP funds and strong inflows in People’s United’s municipal business.

Net interest income totaled $385.9 million in the first quarter of 2021 compared to $382.8 million in the fourth quarter of 2020. Provision for credit losses on loans resulted in a net benefit of $13.6 million. Non-interest income totaled $94.6 million in the first quarter of 2021 compared to $178.2 million in the fourth quarter of 2020. Non-interest expense totaled $311.9 million in the first quarter of 2021 compared to $646.4 million in fourth quarter of 2020.

Commercial loans totaled $32.7 billion at March 31, 2021, a $514 million decrease from December 31, 2020. Average commercial loans totaled $32.5 billion in the first quarter 2021, a $575 million decrease from the fourth quarter 2020. Commercial deposits totaled $23.3 billion at March 31, 2021 compared to $22.9 billion at December 31, 2020. Residential mortgage loans totaled $8.1 billion at March 31, 2021, a $452 million decrease from December 31, 2020. Home equity loans totaled $1.9 billion at March 31, 2021, a $123 million decrease from December 31, 2020. Retail deposits totaled $30.2 billion at March 31, 2021 compared to $29.2 billion at December 31, 2020.

The foregoing is only a summary and is not intended to be a comprehensive statement of People’s United’s unaudited preliminary financial results. Interim financial statements as of and for the period ended March 31, 2021 will be included in People’s United’s Quarterly Report on Form 10-Q to be filed by People’s United with the SEC.

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THE MERGER

This section of the joint proxy statement/prospectus describes material aspects of the merger. This summary may not contain all of the information that is important to you. You should carefully read this entire joint proxy statement/prospectus and the other documents we refer you to for a more complete understanding of the merger. In addition, we incorporate important business and financial information about each of us into this document by reference. You may obtain the information incorporated by reference into this document without charge by following the instructions in the section entitled “Where You Can Find More Information” beginning on page 185.

Terms of the Merger

Each of M&T’s and People’s United’s respective board of directors has approved the merger agreement. The merger agreement provides that, pursuant to the terms and subject to the conditions set forth in the merger agreement, Merger Sub will merge with and into People’s United, with People’s United as the surviving entity, which is referred to as the merger, and as soon as reasonably practicable following the merger, People’s United will merge with and into M&T, with M&T as the surviving entity, which is referred to as the holdco merger. At a date and time following the holdco merger as determined by M&T, People’s United Bank will merge with and into M&T Bank, with M&T Bank as the surviving bank, which is referred to as the bank merger.

In the merger, each share of People’s United common stock issued and outstanding immediately prior to the effective time, including each People’s United director restricted share and except for certain shares owned by M&T or People’s United, will be converted into the right to receive 0.118 of a share of M&T common stock. M&T will not issue any fractional shares of M&T common stock in the merger. Instead, a former holder of People’s United common stock who otherwise would have received a fraction of a share of M&T common stock will receive for the fraction of a share an amount in cash (rounded to the nearest cent) based on the M&T closing share value.

In the merger, each share of People’s United preferred stock issued and outstanding immediately prior to the effective time will be converted into the right to receive one (1) share of new M&T preferred stock. For a description of the terms of the new M&T preferred stock, see the section entitled “Description of New M&T Preferred Stock” beginning on page 157.

M&T shareholders are being asked to approve the M&T charter amendment proposal and the M&T share issuance proposal and People’s United stockholders are being asked to approve the People’s United merger proposal. See the section entitled “The Merger Agreement” beginning on page 119 for additional and more detailed information regarding the legal documents that govern the merger, including information about the conditions to the completion of the merger and the provisions for terminating or amending the merger agreement.

Background of the Merger

As part of the ongoing consideration and evaluation of their respective long-term prospects and strategies, each of M&T’s and People’s United’s boards of directors and managements have regularly reviewed and assessed their respective business strategies and objectives, including assessments of potentially available strategic growth opportunities, as part of their respective efforts to enhance value for their respective shareholders and stockholders and deliver the best possible services to their respective customers and communities. These reviews have focused on, among other things, prospects and developments in the financial services industry, the regulatory environment and the economy generally, and the implications of such developments for financial institutions generally and M&T and People’s United in particular. These reviews have also included assessments of ongoing consolidation in the financial services industry and the benefits and risks to M&T and People’s United, respectively, and their respective shareholders and stockholders of strategic combinations. Both M&T and People’s United have regularly pursued acquisitions and other business combinations as a means to achieve their respective strategic goals.

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Mr. René F. Jones, M&T’s chairman and chief executive officer, and Mr. John P. Barnes, People’s United’s chairman and chief executive officer, have periodically discussed trends in the financial services industry and matters of mutual interest to their respective institutions. These discussions have occurred during the course of investor and banking industry conferences and social and community settings. In addition and prior to the communications described below, Messrs. Jones and Barnes had on several occasions discussed the potential strategic benefits of a business combination between the two companies, but these discussions were preliminary and no specific price or other terms were discussed or agreed.

On December 23, 2020, Mr. Jones called Mr. Barnes to inquire about People’s United’s interest in discussing the possibility of a merger between the two companies. Mr. Barnes briefed Mr. George Carter, People’s United’s lead director, regarding his conversation with Mr. Jones. Mr. Carter expressed his support for Mr. Barnes to engage in preliminary discussions with M&T regarding the feasibility and potential benefits of a possible merger with M&T. On December 28, 2020, Mr. Jones called Mr. Barnes to discuss dates for an in person meeting to discuss a potential merger in greater detail. Messrs. Jones and Barnes spoke again on January 4, 2021 about the potential benefits of a stock-for-stock merger and the possible terms of such a transaction. Based on these conversations, both chief executive officers agreed that it would be useful to meet in person to further explore a possible business combination.

On January 7, 2021, Messrs. Jones and Barnes met to discuss the merits of exploring a potential transaction in which M&T would acquire People’s United in a stock-for-stock transaction, and exchanged their respective preliminary views regarding valuation, which included a discussion of potential exchange ratios of 0.118 to 0.12 (representing an approximately 28% pro forma ownership by People’s United common stockholders in the combined company and a market premium at that time of approximately 15%). Messrs. Jones and Barnes also discussed transaction structure, community commitments, employee retention matters, governance and potential post-merger arrangements with Mr. Barnes and Mr. Kirk W. Walters, People’s United’s senior executive vice president, corporate development & strategic planning, and other terms. Messrs. Jones and Barnes agreed to review these matters with their respective boards of directors and continue to discuss the potential financial and other terms of a transaction (including potential frameworks for establishing the exchange ratio) to see if such a transaction on mutually agreeable terms was feasible.

Following this meeting, Mr. Barnes briefed Mr. Carter on the discussions at the meeting, and over the course of the following week, Mr. Barnes also discussed the opportunity of exploring a potential transaction with each of the other People’s United directors.

On January 14, 2021, the executive committee of the M&T board of directors held a meeting. At the meeting, Mr. Jones informed the executive committee members of a potential transaction with People’s United, including discussing the strategic rationale of the potential transaction. The members of the executive committee discussed the terms of the potential transaction, including potential frameworks for determining the exchange ratio, and potential synergies. Mr. Jones also informed the executive committee members that he would report the potential transaction to the other directors at the upcoming meeting of the M&T board of directors to be held on January 20, 2021.

During the weeks following the January 7, 2021 meeting between the two companies’ chief executive officers, the two companies and their advisors discussed potential frameworks for establishing the exchange ratio (which frameworks would take into account, among other factors, the pro forma ownership of M&T shareholders and People’s United common stockholders in the combined company, the potential premium that People’s United common stockholders would receive in a potential transaction, relative market prices of M&T’s and People’s United’s common stock and other valuation-related factors), as well as governance, employee retention and community issues.

On January 20, 2021, at a meeting of the M&T board of directors, Mr. Jones informed members of the board that management was considering the strategic and financial implications for M&T of a possible acquisition of

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People’s United. M&T management discussed management’s approach to the proposed transaction and the risks and opportunities of the proposed transaction, including, among other matters, the potential financial terms (including potential frameworks proposed by each side for determining the exchange ratio), governance and community considerations and cultural alignment, timing and regulatory implications of the potential transaction. Members of M&T management responded to various questions from the directors regarding the proposed transaction. Following the discussion, the M&T board of directors expressed support for the proposed transaction based on the range of potential terms and authorized M&T management to proceed with their negotiations of a potential acquisition of People’s United consistent with those terms.

On January 21, 2021, the People’s United board of directors held a meeting to discuss the potential transaction with M&T, with representatives of KBW and Simpson Thacher & Bartlett LLP (“Simpson Thacher”), legal counsel to People’s United, in attendance. Messrs. Barnes and Walters reported to the People’s United board of directors on the various discussions they and other representatives of People’s United management and People’s United’s financial and legal advisors had with representatives of M&T regarding the potential transaction, including potential frameworks for establishing the exchange ratio and governance, employee retention and community issues. A representative of KBW provided the People’s United board of directors with, among other information, an overview of the transactional landscape in the banking industry, publicly available information regarding M&T’s and People’s United’s financial and operating performance, potential strategic considerations for a merger with M&T, including the potential for certain strategic and operational benefits that could result from a business combination with M&T, and other potential strategic alternatives for People’s United, including a group of other potential merger partners. A representative of Simpson Thacher reviewed with the People’s United board of directors the directors’ fiduciary duties under Delaware law and then discussed with the People’s United board of directors the terms for the potential transaction that were being discussed between People’s United and M&T. Following discussion, the People’s United directors expressed their support for continuing to explore the feasibility and potential benefits of a potential transaction and directed Messrs. Barnes and Walters and other members of People’s United management, with the assistance of KBW and Simpson Thacher, to continue their discussions and negotiations with M&T and its advisors regarding such a transaction.

Over the following weeks, Messrs. Jones and Barnes and other members of M&T’s and People’s United’s management, with the assistance of their respective companies’ financial and legal advisors, continued to discuss and negotiate the terms of the potential transaction.

On January 25, 2021, M&T and People’s United executed a mutual nondisclosure agreement in order to facilitate more detailed discussions of a potential business combination and reciprocal due diligence efforts. People’s United made available to M&T, and M&T made available to People’s United, documents for mutual due diligence review in virtual data rooms. Through February 21, 2020, the parties engaged in mutual due diligence, including through a series of virtual due diligence meetings and telephone calls between the parties and their respective representatives to discuss relevant topics.

Between January 15, 2021 and January 28, 2021, the parties and their advisors held numerous meetings regarding the exchange ratio and the other terms of the potential transaction. On January 28, 2021, Messrs. Jones and Barnes agreed, subject to completion of the mutual due diligence reviews and negotiation of other mutually agreeable transaction terms, to propose to their respective boards of directors that the exchange ratio in the proposed transaction be fixed at 0.118, which would result in People’s United stockholders owning approximately 28% of the combined company following the completion of the proposed merger.

On February 3, 2021, M&T and People’s United executed a mutual exclusivity agreement pursuant to which each party agreed, until the earlier of the execution of a definitive agreement and 11:59 p.m. New York City time on February 28, 2021, to negotiate exclusively with the other party regarding a possible business combination.

On February 4, 2021, the People’s United board of directors held a meeting to discuss the potential transaction, with representatives of KBW, J.P. Morgan and Simpson Thacher in attendance. Mr. Barnes updated the People’s

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United board of directors regarding the discussions between People’s United and M&T and their respective advisors since the last People’s United board of directors meeting, including that he and Mr. Jones had preliminarily agreed to move forward on the basis of an exchange ratio of 0.118, subject to board of directors approval, and the status of M&T’s ongoing due diligence review of People’s United. Representatives of KBW then reviewed with the People’s United board of directors certain financial aspects of the potential transaction based on the proposed exchange ratio. A representative of Simpson Thacher then discussed various terms of the potential transaction that were being discussed between People’s United and M&T. After Messrs. Barnes and Walters had left the meeting, the People’s United directors discussed the proposed agreements to be entered into with Messrs. Barnes and Walters in connection with and to be effective upon the closing of the potential transaction, which based on discussions with M&T, included three-year comprehensive non-competition / non-solicitation agreements.

On February 10, 2021, Sullivan & Cromwell LLP (“Sullivan & Cromwell”), legal counsel to M&T, shared with Simpson Thacher a first draft of the proposed merger agreement. From February 10, 2021 until February 21, 2021, M&T’s and People’s United’s legal advisors negotiated the proposed merger agreement and other transaction documents.

On February 11, 2021, the People’s United board of directors held a meeting to discuss recent developments and updates regarding the ongoing discussions with respect to a potential transaction with M&T, including regarding the terms that were still being negotiated between the parties, the mutual due diligence review and the timing for a potential transaction announcement.

On February 12, 2021, Mr. Jones updated the executive committee of the M&T board of directors regarding M&T’s possible acquisition of People’s United, including a discussion of the regulatory implications of the potential transaction.

On February 17, 2021, the boards of directors of M&T and M&T Bank held a joint meeting to discuss the potential transaction with People’s United, with representatives of Lazard and Sullivan & Cromwell in attendance. Mr. Jones provided the directors with an update on the strategic and financial implications for M&T of the potential transaction. M&T’s general counsel and a representative of Sullivan & Cromwell then provided the M&T and M&T Bank boards of directors with an overview of certain legal considerations, including the directors’ fiduciary duties in connection with their consideration of the potential transaction with People’s United. Subsequently, various members of M&T management provided the directors with updates regarding the status and key findings of M&T’s due diligence review of People’s United and provided various other updates on the status of the potential transaction. Representatives of Lazard then provided an overview of various aspects of the potential transaction from a financial perspective, including a market perspective on People’s United, the pro forma impact of the proposed transaction on M&T, and perspectives from precedent transactions. Representatives of Sullivan & Cromwell then provided an overview of the current drafts of the transaction agreements and legal process. The meeting recessed until February 19, 2021.

On February 18, 2021, the People’s United board of directors held a meeting to discuss, among other matters, the potential transaction with M&T, with representatives of KBW, J.P. Morgan and Simpson Thacher in attendance. Mr. Barnes provided an update regarding the status of discussions and negotiations of a potential transaction with M&T since the February 4, 2021 People’s United board of directors meeting. KBW and J.P. Morgan each reviewed and discussed with the People’s United board of directors, among other matters, the financial aspects of the proposed transaction and their preliminary financial analyses based on the proposed 0.118 exchange ratio. Mr. Walters then reviewed with the People’s United board of directors the status and process of the mutual due diligence of M&T and People’s United, including the key findings of People’s United’s due diligence review of M&T. A Simpson Thacher representative reviewed with the People’s United board of directors certain legal considerations, including the directors’ fiduciary duties in connection with their consideration of a potential transaction with M&T, and the principal terms of the draft merger agreement. After Messrs. Barnes and Walters had left the meeting, the remaining People’s United directors reviewed the terms of the proposed

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non-competition agreements to be entered into with Messrs. Barnes and Walters in connection with a potential transaction, to become effective upon completion of the transaction. Following discussion, and after taking into consideration the favorable recommendation of People’s United’s compensation committee, the People’s United directors approved the proposed agreements. For a description of such agreements, see “—Interests of Certain People’s United Directors and Executive Officers in the Merger” beginning on page 104.

During the rest of that day and through February 21, 2021, M&T’s and People’s United’s management teams, with the assistance of the parties’ respective legal advisors, continued to finalize the merger agreement and other transaction documents.

On February 19, 2021, the M&T and M&T Bank boards of directors resumed its joint meeting which had commenced on February 17, 2021. Representatives of Lazard and Sullivan & Cromwell were in attendance. Mr. Jones noted that the management was proceeding with steps to move forward with the potential transaction, summarizing the progress made since the M&T and M&T Bank boards of directors recessed on February 17, 2021. A representative of M&T management updated the directors on the final terms of the proposed merger agreement and reported that the negotiations were nearly complete. Representatives of Lazard then presented its fairness analysis and rendered to the M&T board of directors its oral opinion, which was confirmed by a written opinion dated February 19, 2021, to the effect that, as of that date and subject to the procedures followed, assumptions made, matters considered and qualifications and limitations on the review undertaken as set forth in such opinion, the exchange ratio in the proposed transaction was fair, from a financial point of view, to M&T. See “The Merger—Opinion of M&T’s Financial Advisor” beginning on page 66. Representatives of Lazard also responded to questions from the directors. The directors then engaged in a discussion regarding various aspects of the potential transaction, including the factors described under the section of this joint proxy statement/prospectus entitled “—M&T’s Reasons for the Merger; Recommendation of the M&T Board of Directors.” Following these discussions, Mr. Jones presented management’s recommendation for the approval of resolutions authorizing M&T to enter into the merger agreement. The directors were then informed that their written approval would be sought in the form of a unanimous written consent, which proposal would be e-mailed to them immediately following the conclusion of the meeting.

On February 20, 2021, the M&T board of directors, via a unanimous written consent, effective as of that date, determined that the merger agreement and the transactions contemplated by the merger agreement (including the mergers, the M&T charter amendment and the M&T share issuance) were advisable and fair to and in the best interests of M&T and its shareholders, approved and adopted the merger agreement and the transactions contemplated by the merger agreement (including the mergers, the M&T charter amendment and the M&T share issuance), and recommended the approval and adoption by M&T shareholders of the M&T charter amendment proposal, the M&T share issuance proposal and the other matters to be voted upon at the M&T special meeting in accordance with the merger agreement. See “—M&T’s Reasons for the Merger; Recommendation of the M&T Board of Directors.”

On February 20, 2021, the People’s United board and the People’s United Bank board of directors held a joint meeting to discuss the potential transaction with M&T, with representatives of KBW, J.P. Morgan and Simpson Thacher in attendance. Mr. Barnes updated the People’s United board of directors on the final negotiations with M&T relating to the potential transaction. A representative of Simpson Thacher updated the directors on the final terms of the proposed merger agreement. KBW and J.P. Morgan then each discussed the updates to the financial aspects of the potential transaction and the financial analyses they each had reviewed with the People’s United board of directors at the February 18, 2021 meeting. The KBW and J.P. Morgan representatives also observed, among other things, that, based on the respective trading prices of the two companies’ shares through the close of trading on February 19, 2021, the proposed exchange ratio of 0.118 represented a 13% premium to People’s United common stock closing price on February 19, 2021 and a pro forma ownership by People’s United common shareholders in the combined company of approximately 28%. Following the discussion, KBW and J.P. Morgan each rendered to the People’s United board of directors their respective firms’ opinion, which in each case was initially rendered orally and confirmed by a written opinion dated February 20, 2021, to the effect

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that, as of that date and subject to the procedures followed, assumptions made, matters considered and qualifications and limitations on the review undertaken as set forth in each such opinion, the exchange ratio in the proposed merger was fair, from a financial point of view, to the holders of People’s United common stock. See “—Opinions of People’s United Financial Advisors—Opinion of Keefe, Bruyette & Woods, Inc.” and “—Opinions of People’s United Financial Advisors—Opinion of J.P. Morgan Securities LLC” beginning on pages 78 and 91, respectively. Following further discussion, during which the directors considered the matters reviewed and discussed at that meeting and all prior meetings, including the factors described under the section of this joint proxy statement/prospectus entitled “—People’s United’s Reasons for the Merger; Recommendation of the People’s United Board of Directors,” the People’s United board of directors unanimously determined that the merger agreement and the transactions contemplated by the merger agreement were advisable and fair to and in the best interests of Peoples’ United and its stockholders, and approved the merger agreement, the merger and the other transactions contemplated by the merger agreement and recommended that People’s United common stockholders adopt the merger agreement.

In the evening of February 21, 2021, M&T and People’s United executed the merger agreement. The transaction was announced in the morning of February 22, 2021, before the opening of the financial markets in New York, in a press release jointly issued by M&T and People’s United.

M&T’s Reasons for the Merger; Recommendation of M&T’s Board of Directors

After careful consideration, the M&T board of directors, via a unanimous written consent effective as of February 20, 2021, (i) determined that the merger agreement and the transactions contemplated by the merger agreement (including the mergers, the M&T charter amendment and the M&T share issuance) were advisable and fair to and in the best interests of M&T and its shareholders, (ii) approved and adopted the merger agreement and the transactions contemplated by the merger agreement (including the mergers, the M&T charter amendment and the M&T share issuance), and (iii) recommended the approval and adoption by M&T shareholders of the M&T charter amendment proposal, the M&T share issuance proposal and the other matters to be voted upon at the M&T special meeting in accordance with the merger agreement. In reaching this decision, the M&T board of directors evaluated the merger agreement, the mergers and the other matters contemplated by the merger agreement in consultation with M&T’s senior management, as well as with M&T’s legal and financial advisors, and considered a number of factors, including the following:

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The M&T board of directors also considered the potential risks related to the transaction. The board concluded that the anticipated benefits of combining with People’s United were likely to outweigh these risks substantially. These potential risks included:

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The foregoing discussion of the information and factors considered by the M&T board of directors is not intended to be exhaustive, but includes the material factors considered by the board. In reaching its decision to approve the merger agreement and the transactions contemplated by the merger agreement, the M&T board of directors did not quantify or assign any relative weights to the factors considered, and individual directors may have given different weights to different factors. The board considered all these factors as a whole, including discussions with, and questioning of, M&T’s management and M&T’s independent financial and legal advisors, and overall considered the factors to support its determination.

For the reasons set forth above, the M&T board of directors determined that the merger agreement and the transactions contemplated thereby (including the mergers, the M&T charter amendment and the M&T share issuance) are advisable and fair to and in the best interests of M&T and its shareholders.

In considering the recommendation of the M&T board of directors, you should be aware that certain directors and executive officers of M&T may have interests in the merger that are different from, or in addition to, interests of M&T shareholders generally and may create potential conflicts of interest.

It should be noted that this explanation of the reasoning of the M&T board of directors and all other information presented in this section is forward-looking in nature and, therefore, should be read in light of the factors discussed in the section entitled “Cautionary Statement Regarding Forward-Looking Statements” on page 32.

Opinion of M&T’s Financial Advisor

M&T retained Lazard as its financial advisor in connection with the transaction. In connection with this engagement, the M&T board of directors requested that Lazard evaluate the fairness, from a financial point of view, of the exchange ratio to M&T.

On February 19, 2021, Lazard rendered to the M&T board of directors its oral opinion, subsequently confirmed in a written opinion dated February 19, 2021, that, as of such date, and based upon and subject to the assumptions, procedures, matters, qualifications and limitations set forth therein, the exchange ratio was fair, from a financial point of view, to M&T.

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The full text of Lazard’s written opinion, dated February 19, 2021, which describes the assumptions made, procedures followed, matters considered and qualifications and limitations upon the review undertaken by Lazard in preparing its opinion, is attached as Annex D to this joint proxy statement/prospectus and is incorporated by reference into this joint proxy statement/prospectus. The summary of the written opinion of Lazard, dated February 19, 2021, set forth below is qualified in its entirety by the full text of Lazard’s written opinion attached as Annex D to this joint proxy statement/prospectus. Lazard’s financial advisory services and opinion were provided for the use and benefit of the M&T board of directors (in their capacity as directors and not in any other capacity) in connection with its evaluation of the transaction, and addressed only the fairness, from a financial point of view, as of the date thereof, of the exchange ratio to M&T. Lazard’s opinion is not intended to and does not constitute a recommendation to any M&T shareholder or any other person as to how such M&T shareholder or person should vote or act with respect to the merger or any matter relating thereto.

The full text of Lazard’s written opinion should be read carefully in its entirety for a description of the assumptions made, procedures followed, matters considered and qualifications and limitations upon the review undertaken by Lazard in preparing its opinion.

In connection with its opinion, Lazard:

Lazard assumed and relied upon the accuracy and completeness of the foregoing information, without independent verification of such information. Lazard did not conduct any independent valuation or appraisal of any of the assets or liabilities (contingent or otherwise) of People’s United, M&T, People’s United Bank or M&T

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Bank or concerning the solvency or fair value of People’s United, M&T, People’s United Bank or M&T Bank, and Lazard was not furnished with any such valuation or appraisal. With respect to the financial forecasts utilized in Lazard’s analyses, including those related to projected synergies and other benefits anticipated by the management of M&T to be realized from the transaction, Lazard assumed, with the consent of M&T, that they were reasonably prepared on bases reflecting the best currently available estimates and judgments as to the future financial performance of People’s United and M&T, respectively, and such synergies and other benefits. In addition, Lazard assumed, with the consent of M&T, that such financial forecasts and projected synergies and other benefits will be realized in the amounts and at the times contemplated thereby. Lazard assumed no responsibility for and expressed no view as to any such forecasts or the assumptions on which they were based, including with respect to the potential effects of the COVID-19 pandemic on such forecasts or assumptions.

Further, Lazard’s opinion was necessarily based on economic, monetary, market and other conditions as in effect on, and the information made available to Lazard as of, the date of its opinion. Lazard assumed no responsibility for updating or revising its opinion based on circumstances or events occurring after the date of its opinion. Lazard further noted that the volatility and disruption in the credit and financial markets relating to, among other things, the COVID-19 pandemic, may or may not have an effect on M&T, People’s United, M&T Bank or People’s United Bank and that Lazard was not expressing an opinion as to the effects of such volatility or such disruption on any of them. Lazard did not express any opinion as to the prices at which shares of M&T’s common stock or People’s United’s common stock may trade at any time subsequent to the announcement of the transaction. Lazard’s opinion did not address the relative merits of the transaction as compared to any other transaction or business strategy in which M&T might engage or the merits of the underlying decision by M&T to engage in the transaction.

In rendering its opinion, Lazard assumed, with the consent of M&T, that the transaction would be consummated on the terms described in the merger agreement, without any waiver or modification of any material terms or conditions. Representatives of M&T advised Lazard, and Lazard assumed, that the merger agreement, when executed, would conform to the draft reviewed by Lazard in all material respects. Lazard also assumed, with the consent of M&T, that obtaining the necessary governmental, regulatory or third party approvals and consents for the transaction would not have an adverse effect on M&T, People’s United, M&T Bank, People’s United Bank or the transaction. Lazard further assumed, with the consent of M&T, that the merger and the holdco merger, taken together, would qualify for U.S. federal income tax purposes as a reorganization within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended. Lazard did not express any opinion as to any tax or other consequences that might result from the transaction, nor does its opinion address any legal, tax, regulatory or accounting matters, as to which Lazard understood that M&T obtained such advice as it deemed necessary from qualified professionals. Lazard noted that it is not an expert in the evaluation of allowance for loan losses, and Lazard neither made an independent evaluation of the adequacy of the allowance for loan losses at M&T Bank or People’s United Bank nor examined any individual loan credit files of M&T Bank or People’s United Bank, and, as a result, Lazard assumed, with the consent of M&T, that the aggregate allowances for loan losses of M&T Bank and People’s United Bank were adequate. Lazard expressed no view or opinion as to any terms or other aspects (other than the exchange ratio to the extent expressly specified in its opinion) of the transaction, including, without limitation, the form or structure of the transaction or any agreements or arrangements entered into in connection with, or contemplated by, the transaction, including with respect to the mergers. In addition, Lazard expressed no view or opinion as to the fairness of the amount or nature of, or any other aspects relating to, the compensation to any officers, directors or employees of any parties to the transaction, or class of such persons, relative to the exchange ratio or otherwise.

Summary of Lazard’s Financial Analyses

The following is a summary of the material financial analyses reviewed with the M&T board of directors in connection with Lazard’s opinion, dated as of February 19, 2021. The summary of Lazard’s analyses provided below is not a complete description of the analyses underlying Lazard’s opinion. The preparation of a fairness opinion is a complex process involving various determinations as to the most appropriate and relevant methods

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of analysis and the application of those methods to particular circumstances, and, therefore, is not readily susceptible to summary description.

In arriving at its opinion, Lazard considered the results of all of the analyses undertaken by it and assessed as a whole and did not draw, in isolation, conclusions from or with regard to any particular factor or analysis considered by it. Rather, Lazard made its determination as to fairness on the basis of its experience and professional judgment after considering the results of all of the analyses. Considering selected portions of the analyses in the summary set forth below, without considering the analyses as a whole, could create an incomplete or misleading view of the analyses underlying Lazard’s opinion.

For purposes of its analyses, Lazard considered industry performance, general business, economic, market and financial conditions, and other matters, many of which are beyond the control of M&T and People’s United. No company, business or transaction used in Lazard’s analyses as a comparison is identical to M&T, People’s United, the combined company or the transaction, and an evaluation of the results of those analyses is not entirely mathematical. Rather, Lazard’s analyses involve complex considerations and judgments concerning financial and operating characteristics and other factors that could affect the public trading or other values of the companies, businesses or transactions used in Lazard’s analyses. The estimates contained in Lazard’s analyses and the ranges of valuations resulting from any particular analysis are not necessarily indicative of actual values or predictive of future results or values, which may be significantly more or less favorable than those suggested by Lazard’s analyses. In addition, analyses relating to the value of companies, businesses or securities do not purport to be appraisals or to reflect the prices at which companies, businesses or securities actually may be sold. Accordingly, the estimates used in, and the results derived from, Lazard’s analyses are inherently subject to substantial uncertainty.

The summary of the analyses provided below includes information presented in tabular format. In order to fully understand Lazard’s analyses, the tables must be read together with the full text of the accompanying summary. The tables alone do not constitute a complete description of Lazard’s analyses. Considering the data in the tables below without considering the full description of the analyses, including the methodologies and assumptions underlying the analyses, could create a misleading or incomplete view of Lazard’s analyses.

Except as otherwise noted, the quantitative information used in the analyses, to the extent that it was based on market data, was based on market data as it existed at the close of the market on February 17, 2021, and is not necessarily indicative of current market conditions.

Public Trading Comparables Analysis

Lazard performed a public trading comparables analysis, which is designed to provide an implied trading value of a company by comparing it to selected companies with similar characteristics to the company. Lazard compared certain financial information of People’s United and M&T with publicly available information for the selected companies listed below, which are referred to, respectively, as the “People’s United selected companies” and the “M&T selected companies.” The People’s United selected companies and the M&T selected companies were chosen based on Lazard’s knowledge of the industry and because these companies have businesses that may be considered similar to People’s United and M&T, respectively. The People’s United selected companies consisted of all publicly traded banks headquartered in the Mid-Atlantic and Northeast regions with total assets between $20 billion and $100 billion, excluding announced merger targets. The M&T selected companies consisted of publicly traded United States banks with total assets between $75 billion and $600 billion and business models comparable, in Lazard’s professional judgment, to M&T.

With respect to the selected companies, the information Lazard presented included:

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In all instances, multiples were based on closing stock prices on February 17, 2021. For each of the following analyses performed by Lazard, financial and market data for the selected companies were based on the most recent publicly available information, including Wall Street research consensus estimates and information provided by S&P Global Market Intelligence.

The multiples calculated by Lazard for the People’s United selected companies are as follows:

The multiples calculated by Lazard for the M&T selected companies are as follows:

Based on the analysis of the relevant metrics for each of the selected banks and its experience and professional judgment, Lazard selected a range of multiples and applied this range of multiples to the relevant financial statistics for People’s United and M&T, as applicable.

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For purposes of this analysis, with respect to People’s United, Lazard utilized estimated earnings per share for 2021 and 2022, as set forth in “—Certain Unaudited Prospective Financial Information—Certain Stand-Alone People’s United Prospective Financial Information Used by Lazard,” and tangible book value per share of People’s United as of December 31, 2020, as calculated by S&P Global Market Intelligence. Lazard estimated the implied trading value per share of People’s United common stock as of February 17, 2021, as follows:

For purposes of this analysis, with respect to M&T, Lazard utilized estimated earnings per share for 2021 and 2022, as set forth in “—Certain Unaudited Prospective Financial Information—Certain Stand-Alone M&T Prospective Financial Information Used by Lazard,” and tangible book value per share of M&T as of December 31, 2020, as calculated by S&P Global Market Intelligence. Lazard estimated the implied trading value per share of M&T common stock as of February 17, 2021, as follows:

Applying the foregoing analyses, Lazard then calculated the implied exchange ratio by dividing (i) the low end of the selected range of implied values per share of People’s United common stock of $12.00 by the high end of the selected range of implied values per share of M&T common stock of $150.00 and (ii) dividing the high end of the selected range of implied values per share of People’s United common stock of $17.00 by the low end of the selected range of implied values per share of M&T common stock of $125.00. This analysis indicated a range of implied exchange ratios from 0.0800x to 0.1360x, as compared to the transaction exchange ratio of 0.1180x.

No company in the public trading comparables analysis is identical to People’s United or M&T. In evaluating the People’s United selected companies and the M&T selected companies, Lazard made judgments and assumptions with regard to industry performance, general business, economic, market and financial conditions and other matters, many of which are beyond the control of People’s United or M&T, such as the impact of competition on the respective businesses of People’s United and M&T or the industry generally, industry growth and the absence of any material adverse change in the respective financial condition and prospects of People’s United or M&T or the industry or in the financial markets in general. Mathematical analysis, such as determining the average or median, is not in itself a meaningful method of using peer group data.

Selected Precedent Transactions Analysis

Lazard analyzed certain publicly available information relating to certain acquisition transactions (excluding mergers-of-equals) announced since January 1, 2015 involving target companies in the banking industry in the United States in which the implied transaction value was between $2 billion and $10 billion.

While none of the target companies in the selected transactions is directly comparable to People’s United and none of the selected transactions is directly comparable to the transaction, the target companies in the selected transactions are companies with certain operations that, for the purposes of analysis, may be considered similar to certain operations of People’s United and, as such, for purposes of the analysis, the selected transactions may be considered similar to the transaction.

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Using publicly available information, for each of the selected transactions, Lazard calculated:

In each case, Lazard used publicly available information, including Wall Street research consensus estimates as of the last trading day prior to the announcement of the applicable transaction and information provided by S&P Global Market Intelligence. The selected transactions and the implied multiples calculated for the transactions are set forth below.

Based on the analysis of the relevant metrics for each of the selected transactions and its experience and professional judgment, Lazard selected a range of multiples and applied this range of multiples to the relevant financial statistics for People’s United. For purposes of this analysis, Lazard utilized estimated earnings per share for the twelve months following the last day for which it had reported financials (December 31, 2020), as set forth in “—Certain Unaudited Prospective Financial Information—Certain Stand-Alone People’s United Prospective Financial Information Used by Lazard,” and tangible book value per share of People’s United as of December 31, 2020, as calculated by S&P Global Market Intelligence.

Lazard estimated the implied trading value per share of People’s United common stock as of February 17, 2021, as follows:

Applying the foregoing analysis, Lazard then calculated the implied exchange ratio by dividing (i) the low end of the selected range of implied values per share of People’s United common stock of $16.00 by the high end of the selected range of values per share of M&T common stock implied by the above public trading comparables

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analysis of $150.00 and (ii) the high end of the selected range of implied values per share of People’s United common stock of $21.00 by the low end of the selected range of values per share of M&T common stock implied by the above public trading comparables analysis of $125.00. This analysis indicated a range of implied exchange ratios from 0.1067x to 0.1680x, as compared to the transaction exchange ratio of 0.1180x.

Dividend Discount Analyses

Lazard performed a dividend discount analysis of shares of People’s United common stock and M&T common stock. A dividend discount analysis is a valuation methodology used to derive a valuation of an entity by adding the estimated dividends expected to be paid to shareholders through a specified forecast period, in this case, December 31, 2025, to the residual value of the entity at the end of the forecast period. This sum is then discounted to its “present value” using a range of selected discount rates. “Present value” refers to the current value of future cash flows or amounts and is obtained by discounting those future cash flows or amounts to a specified date, in this case, February 18, 2021, by a discount rate that takes into account macroeconomic assumptions and estimates of risk, the opportunity cost of capital, expected returns and other appropriate factors. In connection with this analysis, at M&T’s direction, Lazard assumed 100% of People’s United’s or M&T’s, as applicable, capital generation above a threshold tangible common equity to tangible assets ratio of 7.50% would be dividended on an annual basis and a 1.00% pre-tax opportunity cost of cash.

People’s United Standalone and Pro Forma Valuation

Using the People’s United stand-alone projections, Lazard performed dividend discount analyses for People’s United, both on a standalone basis as well as on a synergized basis taking into account the expected effects of the transaction based on M&T management’s adjustments described in further detail in “—Certain Unaudited Prospective Financial Information—Certain Estimated Synergies Attributable to the Merger”. At M&T’s direction, Lazard extrapolated the People’s United stand-alone projections through year-end 2026, assuming a 5% and 3% annual growth rate for net income and tangible assets, respectively. Lazard calculated a range of implied values per share of People’s United common stock based on the net present value of projected dividendable cash flows from March 31, 2021 through December 31, 2025.

Lazard based its analysis on a range of terminal forward multiples of 11.0x to 13.0x to the terminal year 2026 estimated earnings and 10.5% to 11.5% cost of equity. Lazard selected its terminal multiples and cost of equity ranges based on, among other things, an analysis of the same for the People’s United selected companies. Utilizing the range of costs of equity and terminal value multiples, Lazard derived an implied valuation range of present value indications per share of People’s United common stock from $12.64 to $14.76 on a standalone basis (the “People’s United Standalone DDM Range”) and $17.70 to $20.77 on a synergized basis taking into account the expected effects of the transaction (the “People’s United Pro Forma DDM Range”).

M&T Standalone Valuation

Using the M&T stand-alone projections, Lazard performed a dividend discount analysis for M&T on a standalone basis. Lazard calculated a range of implied values per share of M&T common stock based on the net present value of projected dividendable cash flows from March 31, 2021 through December 31, 2025.

Lazard based its analysis on a range of terminal forward multiples of 11.0x to 13.0x to the terminal year 2026 estimated earnings and 10.0% to 12.0% cost of equity. Lazard selected its terminal multiples and cost of equity ranges based on, among other things, an analysis of the same for the M&T selected companies. Utilizing the range of costs of equity and terminal value multiples, Lazard derived an implied valuation range of present value indications per share of M&T common stock from $125.92 to $151.44 on a standalone basis (the “M&T Standalone DDM Range”).

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Implied Exchange Ratio

Applying the foregoing analyses, Lazard calculated the implied exchange ratio with respect to People’s United on a standalone basis by dividing (i) the low end of the People’s United Standalone DDM Range of $12.64 by the high end of the M&T Standalone DDM Range of $151.44 and (ii) the high end of the People’s United Standalone DDM Range of $14.76 by the low end of the M&T Standalone DDM Range of $125.92. This analysis indicated a range of implied exchange ratios from 0.0835x to 0.1172x, as compared to the transaction exchange ratio of 0.1180x.

Lazard also calculated the implied exchange ratio with respect to People’s United on a synergized basis taking into account the expected effects of the transaction as described above by (i) dividing the low end of the People’s United Pro Forma DDM Range of $17.70 by the high end of the M&T Standalone DDM Range of $151.44 and (ii) dividing the high end of the People’s United Pro Forma DDM Range of $20.77 by the low end of the M&T Standalone DDM Range of $125.92. This analysis indicated a range of implied exchange ratios from 0.1168x to 0.1650x, as compared to the transaction exchange ratio of 0.1180x.

Other Analyses

The analyses and data described below were presented to the M&T board of directors for informational purposes only and did not provide the basis for the rendering of Lazard’s opinion.

People’s United Dividend Discount Analysis

Lazard performed an additional dividend discount analysis for People’s United on an alternative synergized basis taking into account the expected effects of the transaction. Lazard calculated a range of implied values per share of People’s United common stock based on the net present value of projected dividendable cash flows from March 31, 2021 through December 31, 2025.

Historical Trading Price Analysis

Lazard calculated the implied exchange ratio on each trading day during the one-year period ended February 17, 2021, by dividing the closing share price of People’s United common stock by the closing share price of M&T common stock.

Analyst Price Targets

Lazard reviewed publicly available equity research analyst stock price targets, which indicated target prices that ranged from $14.00 to $17.00 per share for People’s United common stock and $131.00 to $166.00 per share for M&T common stock.

General

In connection with Lazard’s services as financial advisor to M&T, M&T has agreed to pay Lazard an aggregate fee for such services of $20 million, $4 million of which became payable upon the rendering of Lazard’s opinion and the remainder of which is contingent upon the consummation of the transaction. M&T may also, in its sole discretion, pay Lazard up to an additional $3 million upon the consummation of the transaction. M&T also agreed to reimburse Lazard for certain expenses incurred in connection with Lazard’s engagement and to indemnify Lazard and certain related persons under certain circumstances against certain liabilities that may arise from or relate to Lazard’s engagement.

In the ordinary course, Lazard and its affiliates and employees may trade securities of People’s United, M&T and certain of their respective affiliates for their own accounts and for the accounts of their customers and,

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accordingly, may at any time hold a long or short position in such securities, and may also trade and hold securities on behalf of People’s United, M&T and certain of their respective affiliates. The issuance of Lazard’s opinion was approved by the Opinion Committee of Lazard.

Lazard did not recommend any specific exchange ratio or other consideration to M&T or that any given exchange ratio or other consideration constituted the only appropriate exchange ratio or other consideration for the transaction. Lazard’s opinion and analyses were only one of many factors taken into consideration by the M&T board of directors in its evaluation of the transaction. Consequently, the analyses described above should not be viewed as determinative of the views of the M&T board of directors or M&T management with respect to the exchange ratio provided for in the transaction or as to whether the M&T board of directors would have been willing to determine that a different exchange ratio or other consideration was fair.

Lazard is an internationally recognized investment banking firm providing a full range of financial advisory and securities services. Lazard was selected to act as M&T’s financial advisor because of its qualifications, experience and reputation in investment banking and mergers and its familiarity with M&T and its business.

People’s United’s Reasons for the Merger; Recommendation of People’s United’s Board of Directors

After careful consideration, the People’s United board of directors, at a special meeting held on February 20, 2021, unanimously (i) determined that the merger agreement and the transactions contemplated thereby, including the merger, are in the best interests of People’s United and its stockholders, (ii) declared the merger agreement advisable and (iii) approved the execution, delivery and performance of the merger agreement and the consummation of the transactions contemplated thereby, including the merger. Accordingly, the People’s United board of directors unanimously recommends that the People’s United common stockholders vote “FOR” the People’s United merger proposal, “FOR” the People’s United compensation proposal and “FOR” the People’s United adjournment proposal.

In reaching its decision to approve the merger agreement and the transactions contemplated thereby, including the merger, and to recommend that People’s United’s common stockholders adopt the merger agreement, the People’s United board of directors evaluated the merger agreement, the merger and the other transactions contemplated by the merger agreement in consultation with People’s United management, as well as with People’s United’s financial and legal advisors, and considered a number of factors, including the following:

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The People’s United board of directors also considered the potential risks related to the transaction, but concluded that the anticipated benefits of combining with M&T were likely to outweigh these risks. These potential risks include:

The foregoing discussion of the information and factors considered by the People’s United board of directors is not intended to be exhaustive, but includes the material factors considered by the board. In reaching its decision to approve the merger agreement and the transactions contemplated thereby, including the merger, the People’s United board of directors did not quantify or assign any relative weights to the factors considered, and individual directors may have given different weights to different factors. The People’s United board of directors considered all these factors as a whole in evaluating the merger agreement and the transactions contemplated thereby, including the merger.

For the reasons set forth above, the People’s United board of directors determined that the merger agreement and the transactions contemplated by the merger agreement are advisable and fair to and in the best interests of People’s United and its stockholders, and approved the merger agreement and the transactions contemplated thereby, including the merger.

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In considering the recommendation of the People’s United board, you should be aware that certain directors and executive officers of People’s United may have interests in the merger that are different from, or in addition to, interests of stockholders of People’s United generally and may create potential conflicts of interest. The People’s United board of directors was aware of these interests and considered them when evaluating and negotiating the merger agreement and the transactions contemplated thereby, including the merger, and in recommending to People’s United’s common stockholders that they vote in favor of the People’s United merger proposal. See “—Interests of Certain People’s United Directors and Executive Officers in the Merger” beginning on page 104.

It should be noted that this explanation of the reasoning of the People’s United board of directors and all other information presented in this section is forward-looking in nature and, therefore, should be read in light of the factors discussed in the section entitled “Cautionary Statement Regarding Forward-Looking Statements” beginning on page 32.

For the reasons set forth above, the People’s United board of directors unanimously recommends that the holders of People’s United common stock vote “FOR” the People’s United merger proposal and “FOR” the other proposals to be considered at the People’s United special meeting.

Opinions of People’s United’s Financial Advisors

Opinion of Keefe, Bruyette & Woods, Inc.

People’s United engaged KBW to render financial advisory and investment banking services to People’s United, including an opinion to the People’s United board of directors as to the fairness, from a financial point of view, to the common shareholders of People’s United of the exchange ratio in the proposed merger. People’s United selected KBW because KBW is a nationally recognized investment banking firm with substantial experience in transactions similar to the merger. As part of its investment banking business, KBW is continually engaged in the valuation of financial services businesses and their securities in connection with mergers and acquisitions.

As part of its engagement, representatives of KBW attended the meeting of the People’s United board of directors held on February 20, 2021, at which the People’s United board of directors evaluated the proposed transaction. At this meeting, KBW reviewed the financial aspects of the proposed merger and rendered to the People’s United board of directors an opinion to the effect that, as of such date and subject to the procedures followed, assumptions made, matters considered, and qualifications and limitations on the review undertaken by KBW as set forth in its opinion, the exchange ratio in the proposed merger was fair, from a financial point of view, to the holders of People’s United common stock. The People’s United board of directors approved the merger agreement at this meeting.

The description of the opinion set forth herein is qualified in its entirety by reference to the full text of the opinion, which is attached as Annex E to this document and is incorporated herein by reference, and describes the procedures followed, assumptions made, matters considered, and qualifications and limitations on the review undertaken by KBW in preparing the opinion.

KBW’s opinion speaks only as of the date of the opinion. The opinion was for the information of, and was directed to, the People’s United board of directors (in its capacity as such) in connection with its consideration of the financial terms of the transaction. The opinion addressed only the fairness, from a financial point of view, of the exchange ratio in the merger to the holders of People’s United common stock. It did not address the underlying business decision of People’s United to engage in the transaction or enter into the merger agreement or constitute a recommendation to the People’s United board of directors in connection with the transaction, and it does not constitute a recommendation to any holder of People’s United common stock or any shareholder of any other entity as to how to vote in connection with the transaction or any other matter, nor does it constitute a recommendation regarding whether or not any such shareholder should enter into a voting, shareholders’ or affiliates’ agreement with respect to the transaction or exercise any dissenters’ or appraisal rights that may be available to such shareholder.

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KBW’s opinion was reviewed and approved by KBW’s Fairness Opinion Committee in conformity with its policies and procedures established under the requirements of Rule 5150 of the Financial Industry Regulatory Authority.

In connection with the opinion, KBW reviewed, analyzed and relied upon material bearing upon the financial and operating condition of People’s United and M&T and bearing upon the transaction, including, among other things:

KBW’s consideration of financial information and other factors that it deemed appropriate under the circumstances or relevant to its analyses included, among others, the following:

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KBW also performed such other studies and analyses as it considered appropriate and took into account its assessment of general economic, market and financial conditions and its experience in other transactions, as well as its experience in securities valuation and knowledge of the banking industry generally. KBW also participated in discussions held by the managements of People’s United and M&T regarding the past and current business operations, regulatory relations, financial condition and future prospects of their respective companies and such other matters as KBW deemed relevant to its inquiry. KBW was not requested to, and did not, assist People’s United with soliciting indications of interest from third parties regarding a potential transaction with People’s United.

In conducting its review and arriving at its opinion, KBW relied upon and assumed the accuracy and completeness of all of the financial and other information that was provided to it or that was publicly available and KBW did not independently verify the accuracy or completeness of any such information or assume any responsibility or liability for such verification, accuracy or completeness. KBW relied upon the management of People’s United as to the reasonableness and achievability of the publicly available consensus “street estimates” of People’s United and the assumed People’s United long-term growth rates referred to above (and the assumptions and bases therefor), and KBW assumed that all such information was reasonably prepared and represented, or in the case of the People’s United “street estimates” referred to above that such estimates were consistent with, the best currently available estimates and judgments of People’s United management and that the forecasts, projections and estimates reflected in such information would be realized in the amounts and in the time periods estimated. KBW further relied, with the consent of People’s United, upon M&T management as to the reasonableness and achievability of the publicly available consensus “street estimates” of M&T, the assumed M&T long-term growth rates, and the estimates regarding certain pro forma financial effects of the transaction on M&T (including, without limitation, the cost savings and related expenses expected to result or be derived from the transaction), all as referred to above (and the assumptions and bases for all such information), and KBW assumed that all such information was reasonably prepared and represented, or in the case of the M&T “street estimates” referred to above that such estimates were consistent with, the best currently available estimates and judgments of M&T management and that the forecasts, projections and estimates reflected in such information would be realized in the amounts and in the time periods estimated.

It is understood that the portion of the foregoing financial information of People’s United and M&T that was provided to KBW was not prepared with the expectation of public disclosure and that all of the foregoing financial information, including the publicly available consensus “street estimates” of People’s United and M&T, was based on numerous variables and assumptions that are inherently uncertain (including, without limitation, factors related to general economic and competitive conditions and, in particular, assumptions regarding the ongoing COVID-19 pandemic) and, accordingly, actual results could vary significantly from those set forth in such information. KBW assumed, based on discussions with the respective managements of People’s United and M&T and with the consent of the People’s United board of directors, that all such information provided a reasonable basis upon which KBW could form its opinion and KBW expressed no view as to any such information or the assumptions or bases therefor. Among other things, such information assumed that the ongoing COVID-19 pandemic could have an adverse impact, which has been assumed to be limited, on People’s United and M&T. KBW relied on all such information without independent verification or analysis and did not in any respect assume any responsibility or liability for the accuracy or completeness thereof.

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KBW also assumed that there were no material changes in the assets, liabilities, financial condition, results of operations, business or prospects of either People’s United or M&T since the date of the last financial statements of each such entity that were made available to KBW. KBW is not an expert in the independent verification of the adequacy of allowances for loan and lease losses and KBW assumed, without independent verification and with People’s United’s consent, that the aggregate allowances for loan and lease losses for People’s United and M&T are adequate to cover such losses. In rendering its opinion, KBW did not make or obtain any evaluations or appraisals or physical inspection of the property, assets or liabilities (contingent or otherwise) of People’s United or M&T, the collateral securing any of such assets or liabilities, or the collectability of any such assets, nor did KBW examine any individual loan or credit files, nor did it evaluate the solvency, financial capability or fair value of People’s United or M&T under any state or federal laws, including those relating to bankruptcy, insolvency or other matters. Estimates of values of companies and assets do not purport to be appraisals or necessarily reflect the prices at which companies or assets may actually be sold. Such estimates are inherently subject to uncertainty and should not be taken as KBW’s view of the actual value of any companies or assets.

KBW assumed, in all respects material to its analyses:

KBW assumed that the transaction would be consummated in a manner that complies with the applicable provisions of the Securities Act of 1933, as amended, the Securities Exchange Act of 1934, as amended, and all other applicable federal and state statutes, rules and regulations. KBW was further advised by representatives of People’s United that People’s United relied upon advice from its advisors (other than KBW) or other appropriate sources as to all legal, financial reporting, tax, accounting and regulatory matters with respect to People’s United, M&T, the transaction and any related transaction, and the merger agreement. KBW did not provide advice with respect to any such matters.

KBW’s opinion addressed only the fairness, from a financial point of view, as of the date of the opinion, of the exchange ratio in the merger to the holders of People’s United common stock. KBW expressed no view or opinion as to any other terms or aspects of the transaction or any term or aspect of any related transaction (including the bank merger and the termination of People’s United’s Employee Stock Ownership Plan prior to the consummation of the merger), including without limitation, the form or structure of the transaction or any such related transaction, the treatment of outstanding preferred stock and other securities of People’s United in

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the transaction, any consequences of the transaction or any such related transaction to People’s United, its shareholders, creditors or otherwise, or any terms, aspects, merits or implications of any employment, consulting, voting, support, shareholder, charitable giving or other agreements, arrangements or understandings contemplated or entered into in connection with the transaction, any such related transaction, or otherwise. KBW’s opinion was necessarily based upon conditions as they existed and could be evaluated on the date of such opinion and the information made available to KBW through such date. There has been widespread disruption, extraordinary uncertainty and unusual volatility arising from the effects of the COVID-19 pandemic, including the effect of evolving governmental interventions and non-interventions. Developments subsequent to the date of KBW’s opinion may have affected, and may affect, the conclusion reached in KBW’s opinion and KBW did not and does not have an obligation to update, revise or reaffirm its opinion. KBW’s opinion did not address, and KBW expressed no view or opinion with respect to:

In performing its analyses, KBW made numerous assumptions with respect to industry performance, general business, economic, market and financial conditions and other matters, which are beyond the control of KBW, People’s United and M&T. Any estimates contained in the analyses performed by KBW are not necessarily indicative of actual values or future results, which may be significantly more or less favorable than suggested by these analyses. Additionally, estimates of the value of businesses or securities do not purport to be appraisals or to reflect the prices at which such businesses or securities might actually be sold. Accordingly, these analyses and estimates are inherently subject to substantial uncertainty. In addition, KBW’s opinion was among several factors taken into consideration by the People’s United board of directors in making its determination to approve the merger agreement and the transaction. Consequently, the analyses described below should not be viewed as determinative of the decision of the People’s United board of directors with respect to the fairness of the exchange ratio. The type and amount of consideration payable in the merger were determined through negotiation between People’s United and M&T and the decision of People’s United to enter into the merger agreement was solely that of the People’s United board of directors.

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The following is a summary of the material financial analyses presented by KBW to the People’s United board of directors in connection with its opinion. The summary is not a complete description of the financial analyses underlying the opinion or the presentation made by KBW to the People’s United board of directors, but summarizes the material analyses performed and presented in connection with such opinion. The financial analyses summarized below include information presented in tabular format. The tables alone do not constitute a complete description of the financial analyses. The preparation of a fairness opinion is a complex analytic process involving various determinations as to appropriate and relevant methods of financial analysis and the application of those methods to the particular circumstances. Therefore, a fairness opinion is not readily susceptible to partial analysis or summary description. In arriving at its opinion, KBW did not attribute any particular weight to any analysis or factor that it considered, but rather made qualitative judgments as to the significance and relevance of each analysis and factor. Accordingly, KBW believes that its analyses and the summary of its analyses must be considered as a whole and that selecting portions of its analyses and factors or focusing on the information presented below in tabular format, without considering all analyses and factors or the full narrative description of the financial analyses, including the methodologies and assumptions underlying the analyses, could create a misleading or incomplete view of the process underlying its analyses and opinion.

For purposes of the financial analyses described below, KBW utilized an implied transaction value for the merger of $17.70 per outstanding share of People’s United common stock, or approximately $7,518.6 million in the aggregate (inclusive of the implied value of in-the-money People’s United stock options), based on the 0.1180x exchange ratio in the proposed merger and the closing price of M&T common stock on February 19, 2021. In addition to the financial analyses described below, KBW reviewed with the People’s United board of directors for informational purposes, among other things, an implied transaction multiple for the proposed merger (based on the implied transaction value for the merger of $17.70 per outstanding share of People’s United common stock) of 13.8x People’s United’s estimated calendar year 2021 earnings per share (“EPS”) taken from publicly available consensus “street estimates” for People’s United.

People’s United Selected Companies Analysis

Using publicly available information, KBW compared the financial performance, financial condition and market performance of People’s United to M&T and 11 major exchange-traded U.S. banks with total assets between $40 billion and $100 billion. Merger targets, Puerto Rico-headquartered banks and First Citizens BancShares, Inc. were excluded from the selected companies.

The selected companies were as follows:

BOK Financial Corporation

Comerica Incorporated

Cullen/Frost Bankers, Inc.

East West Bancorp, Inc.

First Horizon Corporation

New York Community Bancorp, Inc.

Signature Bank

Synovus Financial Corp.

Valley National Bancorp

Wintrust Financial Corporation

Zions Bancorporation, National Association

To perform this analysis, KBW used profitability and other financial information for the latest 12 months (“LTM”) (or, in the case of dividend yield, most recent completed fiscal quarter annualized) available or as of the end of such period and market price information as of February 19, 2021. KBW also used 2021 and 2022 EPS estimates taken from publicly available consensus “street estimates” for People’s United, M&T and the selected companies. Certain financial data prepared by KBW, and as referenced in the tables presented below, may not

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correspond to the data presented in People’s United’s historical financial statements, or the data prepared by Lazard Frères & Co. LLC and J.P. Morgan Securities LLC presented under the sections “Opinion of M&T’s Financial Advisor” and “Opinions of People’s United’s Financial Advisors—Opinion of J.P. Morgan Securities LLC”, respectively, as a result of the different periods, assumptions and methods used by KBW to compute the financial data presented.

KBW’s analysis showed the following concerning the financial performance of People’s United, M&T and the selected companies:

KBW’s analysis showed the following concerning the financial condition of People’s United and the selected companies:

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In addition, KBW’s analysis showed the following concerning the market performance of People’s United and the selected companies:

No company used as a comparison in the above selected companies analysis is identical to People’s United. Accordingly, an analysis of these results is not mathematical. Rather, it involves complex considerations and judgments concerning differences in financial and operating characteristics of the companies involved.

M&T Selected Companies Analysis

Using publicly available information, KBW compared the financial performance, financial condition and market performance of M&T to 11 selected major exchange-traded U.S. banks with total assets between $75 billion and $600 billion. Merger targets, trust and custody banks (specifically, Bank of New York Mellon Corporation, State Street Corporation, and Northern Trust Corporation) and banks with unique business models (specifically, Capital One Financial Corporation, First Republic Bank and SVB Financial Group) were excluded from the selected companies.

The selected companies were as follows: