In accordance with the resolution of the Annual General Meeting of Metsä Board Corporation (the "Company") held on 20 March 2025, approximately one half of the annual remuneration of the Board of Directors is paid in the Company's B-series shares acquired through public trading. The payment of the remuneration does not affect the number of treasury shares held by the Company. Pursuant to this resolution, and to supplement the remuneration previously paid on 2 May 2025, the following shares have been acquired for and on behalf of Jussi Vanhanen, who commenced as Chairman of the Board of Directors on 1 July 2025, proportionate to the approximately 8.5-month term of chairmanship:

Metsä Board Corporation - Managers' transactions - Vanhanen

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Person subject to the notification requirement

Name: Vanhanen, Jussi

Position: Member of the Board/Deputy member

Issuer: Metsä Board Corporation

LEI: 743700KKB8Q035K38488

Notification type: INITIAL NOTIFICATION

Reference number: 743700KKB8Q035K38488_20250829084345_94

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Transaction date: 2025-08-28

Venue: XHEL

Instrument type: SHARE

ISIN: FI0009000665

Nature of the transaction: RECEIPT OF A SHARE-BASED INCENTIVE

Transaction details

(1): Volume: 3529 Unit price: 0.00 EUR

Aggregated transactions

(1): Volume: 3529 Volume weighted average price: 0.00 EUR

METSÄ BOARD CORPORATION