X0609 4 2026-03-11 0001666134 BLACKLINE, INC. BL 0002124309 Prichard Megan false 21300 VICTORY BLVD., 12TH FLOOR WOODLAND HILLS CA 91367-7734 1 0 Common Stock 2026-03-11 4 A 0 922 0 A 922 D This Form 4 reports an initial grant of restricted stock units to Ms. Prichard following her appointment to the Issuer's board of directors on March 11, 2026. The filing was delayed due to a procedural delay in Ms. Prichard receiving the requisite EDGAR access codes from the SEC. This Form 4 was filed promptly upon receipt of the codes. Represents an initial restricted stock unit ("RSU") award issued pursuant to the Issuer's Outside Director Compensation Policy. Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. 100% of the RSUs will vest the day prior to the Issuer's next annual stockholder meeting, subject to the reporting person's continued service through the applicable vesting date. /s/ Karole Morgan-Prager, Attorney-in-Fact 2026-03-26