X0407 4 2023-06-01 0 0001333274 MERCER INTERNATIONAL INC. MERC 0001742623 Wallace Alan C. SUITE 1120 700 WEST PENDER STREET VANCOUVER A1 V6C 1G8 BRITISH COLUMBIA, CANADA 1 0 0 0 0 Cash Settled Deferred Stock Units 2023-06-01 4 A 0 1925 A Common Stock 1925 7065 D Cash Settled Deferred Stock Units 2023-06-01 4 A 0 11548 A Common Stock 11548 18613 D Cash Settled Deferred Stock Units 2023-06-01 4 A 0 1925 A Common Stock 1925 20538 D Cash Settled Deferred Stock Units 2023-06-01 4 A 0 11548 A Common Stock 11548 32086 D Represents cash-settled deferred stock units ("DSUs") issued by Mercer International Inc. ("Mercer"), at the election of the Reporting Person, in lieu of quarterly cash director retainer under Mercer's non-employee director compensation program for the period from April 1, 2023 to May 31, 2023. Each DSU represents the right to receive a cash payment equal to the fair market value of one share of Mercer's common stock on the redemption date(s) and dividend equivalents after the Reporting Person ceases to be a director of Mercer, unless deferred in accordance with its terms. Mercer subsequently transitioned its non-employee director compensation program from quarterly on a calendar year basis to a program based on the one-year period between annual general meetings, being the general term of office of directors. Represents DSUs issued by Mercer, at the election of the Reporting Person, in lieu of cash director retainer under Mercer's non-employee director compensation program and the Plan in respect of the board term commencing May 31, 2023 and ending at its next regularly scheduled annual general meeting in 2024. Each DSU represents the right to receive a cash payment equal to the fair market value of one share of Mercer's common stock on the redemption date(s) and dividend equivalents after the Reporting Person ceases to be a director of Mercer, unless deferred in accordance with its terms. Represents DSUs issued by Mercer as a grant to the Reporting Person, at the election of the Reporting Person as a quarterly equity grant under Mercer's non-employee director compensation program in respect of the period from April 1, 2023 to May 31, 2023, which vest on the one year anniversary of the grant date. Each DSU represents the right to receive a cash payment equal to the fair market value of one share of Mercer's common stock on the redemption date(s) and dividend equivalents after the Reporting Person ceases to be a director of Mercer, unless deferred in accordance with its terms. Represents DSUs issued by Mercer as a grant to the Reporting Person, at the election of the Reporting Person as an equity grant under Mercer's non-employee director compensation program in respect of the board term commencing May 31, 2023 and ending at its next regularly scheduled annual general meeting in 2024. Each DSU represents the right to receive a cash payment equal to the fair market value of one share of Mercer's common stock on the redemption date(s) and dividend equivalents after the Reporting Person ceases to be a director of Mercer, unless deferred in accordance with its terms. These DSUs vest on the earlier of the one-year anniversary of the grant date or the date of the next regularly scheduled annual general meeting in 2024. /s/ Alan C. Wallace 2023-06-02