Dolphin Drilling Legacy UK Tax Claim

OSLO, Norway, 24th October 2025 - Dolphin Drilling AS (OSE: DDRIL) ("Dolphin") today confirms that His Majesty's Revenue and Customs ("HMRC") in the UK and the Company has reached a position in respect of the outstanding corporation tax liability of GBP 12.2 million, where the Company will repay its debt to HMRC over a period until April 30, 2026. This liability relates to a legacy claim dismissed by the UK Supreme Court on 24 June 2025. Dolphin Drilling is committed to meeting its financial obligations and continuing to focus on its operational and strategic priorities.

Contacts: Ingolf Gillesdal, CFO Phone: +47 920 45 320 Email: Ingolf.gillesdal@dolphindrilling.com

About Dolphin Drilling AS:

Dolphin Drilling AS is an Oslo listed, Aberdeen head-quartered, company which owns and operates a fleet of harsh environment mid-water & deep-water semisubmersible drilling rigs, capable of working worldwide.

This information has been submitted pursuant to the Securities Trading Act § 5-12 and MAR Article 17. The information was submitted for publication at 2025-10-24 14:40 CEST.