The UK Treasury has amended Multinational Top-up Tax regulations to enable HMRC to issue retrospective notices under the OECD’s Pillar Two rules, effective 24 July 2025.
The UK Treasury introduced SI 2025/783 on 30 June 2025, amending the existing Multinational Top-up Tax regulations (SI 2025/406) to allow His Majesty’s Revenue and Customs (HMRC) to issue notices with retrospective effect.
The amendment relates to the UK’s implementation of the OECD’s Pillar Two rules, which address minimum taxation for large multinational enterprises. Under the original 2025 regulations, HMRC could designate certain jurisdictions as Pillar Two territories and specific levies as qualifying or accredited qualifying domestic top-up taxes.
With the amendment taking effect on 24 July 2025, HMRC may now retrospectively apply such designations, aligning UK administration more closely with the evolving global framework.
