HARBOUR ENERGY PLC

("Harbour" or the "Company")

Transaction in Own Shares

Harbour announces that, during the period from 17 August 2026 to 21 August 2026 (the "Reporting Period"), it purchased the following number of its ordinary shares of 0.002 pence each for cancellation under its share buyback programme announced on 6 August 2026.

Aggregated information on shares purchased during the Reporting Period by trading venue

Following the purchase and cancellation of these shares, the Company's total number of ordinary shares in issue will be 1,574,372,803. This information may be used by shareholders to determine whether they are required to notify their interest, or a change to their interest, in the Company under the FCA's Disclosure Guidance and Transparency Rules.

To date, Harbour has purchased 5,953,330 ordinary shares in aggregate for cancellation in connection with this buyback programme.

In accordance with Article 5(1)(b) of the UK Market Abuse Regulation, a full breakdown of the individual purchases of ordinary shares made by Barclays behalf of the Company as part of the share buyback programme during the Reporting Period is available at the link below.

http://www.rns-pdf.londonstockexchange.com/rns/9388R_1-2026-8-24.pdf