BLACKLINE, INC. — Proxy Solicitation & Information Statement 2026

Mar 25, 2026

DEFA14A 1 defa14a2026.htm DEFA14A Document created using Wdesk Copyright 2026 Workiva DEFA14A2026

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

PROXY STATEMENT PURSUANT TO SECTION 14(a) OF THE

SECURITIES EXCHANGE ACT OF 1934

Filed by the Registrant ☒
Filed by a Party other than the Registrant ☐
Check the appropriate box:
☐	Preliminary Proxy Statement
☐	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
☐	Definitive Proxy Statement
☒	Definitive Additional Materials
☐	Soliciting Material Under §240.14a-12

BLACKLINE, INC.
(Name of Registrant as Specified In Its Charter)
(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):
☒	No fee required
☐	Fee paid previously with preliminary materials
☐	Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11

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Your Vote Counts! Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # V91447-P41373 Please check the meeting materials for any special requirements for meeting attendance. BLACKLINE, INC. 21300 VICTORY BLVD, 12TH FLOOR WOODLAND HILLS, CA 91367 BLACKLINE, INC. 2026 Annual Meeting Vote by May 6, 2026 11:59 p.m. Eastern Time You invested in BLACKLINE, 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 7, 2026. Vote Virtually at the Meeting May 7, 2026 9:00 a.m. PT Virtually at: www.virtualshareholdermeeting.com/BL2026 Get informed before you vote View the Notice and Proxy Statement and Form 10-K online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 23, 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.

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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 V91448-P41373 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. 1. Election of Directors For Nominees: 01) Scott Davidson 02) David Henshall 03) Therese Tucker 2. To ratify the appointment of PricewaterhouseCoopers LLP (“PwC”) as the Company’s independent registered public accounting firm for its fiscal year ending December 31, 2026. For 3. Approval, on a non-binding, advisory basis, of the 2025 compensation of the Company’s named executive officers. For 4. The stockholder proposal regarding the declassification of the Board of Directors if properly presented at the Annual Meeting of Shareholders. For NOTE: In their discretion, the proxies are authorized to vote upon such other business as may properly come before the Annual Meeting of Shareholders or any adjournments or postponements thereof.