HARBOUR ENERGY PLC

("Harbour" or the "Company")

Transaction in Own Shares

Harbour announces that it has purchased the following number of its ordinary shares of 0.002 pence each for cancellation under its share buyback programme announced on 7 August 2025.

Aggregated information on Shares purchased according to trading value

Following the purchase and cancellation of these shares, the Company's total number of ordinary shares in issue will be 1,404,868,595. 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 Financial Conduct Authority's Disclosure Guidance and Transparency Rules.

To date, Harbour has purchased 35,254,163 ordinary shares in aggregate for cancellation in connection with this buyback programme. This concludes the current share buyback programme.

In accordance with Article 5(1)(b) of the Market Abuse Regulation (EU) No 596/2014, as it forms part of domestic law of the United Kingdom by virtue of the European Union (Withdrawal) Act 2018 as amended, a full breakdown of the individual purchases of ordinary shares made by Bank of America on behalf of the Company as part of the buy-back programme is available via the link below.

http://www.rns-pdf.londonstockexchange.com/rns/5933O_1-2026-1-12.pdf

Harbour Energy plc LEI: 213800YPC42DYBKVPF97