X0508 4 2026-02-20 0001666134 BLACKLINE, INC. BL 0001688119 Villanova Patrick 21300 VICTORY BLVD., 12TH FLOOR WOODLAND HILLS CA 91367 1 Chief Financial Officer 0 Common Stock 2026-02-20 4 M 0 2395 36.15 A 75220 D Common Stock 2026-02-20 4 M 0 1307 36.15 A 76527 D Common Stock 2026-02-20 4 M 0 5238 36.15 A 81765 D Common Stock 2026-02-20 4 F 0 10573 36.15 D 71192 D The reported shares relate to the portion of a Performance Based Restricted Stock Unit ("PRSU") granted on March 7, 2023 that has vested based on the Issuer's achievement of certain fiscal 2023 performance targets that were set by the Compensation Committee at the time of grant. The reported shares relate to the portion of a PRSU granted on March 17, 2024 that has vested based on the Issuer's achievement of certain fiscal 2024 performance targets that were set by the Compensation Committee at the time of grant. The reported shares relate to the portion of a PRSU granted on April 2, 2025 that has vested based on the Issuer's achievement of certain fiscal 2025 performance targets that were set by the Compensation Committee at the time of grant. The reported shares were withheld to cover the reporting person's tax liability in connection with the vesting of PRSUs and restricted stock units. /s/ Karole Morgan-Prager, Attorney-in-Fact 2026-02-24