Additional Proxy Soliciting Materials (Form DEFA14A)

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Preliminary Proxy Statement

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Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

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Definitive Proxy Statement

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Definitive Additional Materials

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Soliciting Material under §240.14a-12

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No fee required.

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Fee paid previously with preliminary materials.

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Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a6(i)(1) and 0-11

Your Vote Counts! *Please check the meeting materials for any special requirements for meeting attendance. Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # V88228-P45265 WEST PHARMACEUTICAL SERVICES, INC. 2026 Annual Meeting Vote by May 3, 2026 11:59 P.M. EDT. For shares held in a Plan, vote by April 30, 2026 11:59 P.M. EDT. WEST PHARMACEUTICAL SERVICES, INC. C/O BROADRIDGE CORPORATE ISSUER SOLUTIONS P.O. BOX 1342 BRENTWOOD, NY 11717 You invested in WEST PHARMACEUTICAL SERVICES, INC. and it's time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy materials for the shareholder meeting to be held on May 4, 2026. Vote Virtually at the Meeting* May 4, 2026 9:30 AM EDT Virtually at: www.virtualshareholdermeeting.com/WST2026 Get informed before you vote View the Notice and Proxy Statement and 2025 Annual Report on Form 10-K online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 20, 2026. If you would like to request a copy of the material(s) for this and/or future shareholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote. com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy.

THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming shareholder meeting. Please follow the instructions on the reverse side to vote these important matters. Vote at www.ProxyVote.com Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click "Delivery Settings". Voting Items Board Recommends V88229-P45265 1. Election of Directors Nominees: 1a. Mark A. Buthman For 1b. William F. Feehery For 1c. Robert F. Friel For 1d. Eric M. Green For 1e. Janet B. Haugen For 1f. Molly E. Joseph For 1g. Deborah L. V. Keller For 1h. Myla P. Lai-Goldman For 1i. Stephen H. Lockhart For 1j. Douglas A. Michels For 1k. Paolo Pucci For 2. Advisory vote to approve named executive officer compensation. For 3. Ratification of the appointment of our independent registered public accounting firm for 2026. For 4. Shareholder proposal regarding an independent Board Chair policy. Against NOTE: Such other business as may properly come before the meeting or any adjournment thereof.