The exemption of the United States from a global minimum tax agreement is expected to reduce the United Kingdom’s projected tax revenues by approximately £600 million annually, according to a report by the Commons Public Accounts Committee. The committee highlighted that despite the introduction of a 15 percent global minimum corporate tax rate, the risk of multinational companies shifting profits across borders to avoid taxation remains notably high.

Nearly 150 countries, under the framework of the Organisation for Economic Co-operation and Development (OECD), initially agreed to the global minimum tax deal in 2021. However, earlier this year, OECD Secretary-General Mathias Cormann confirmed an arrangement allowing the US to be partially exempt from the agreement. This decision follows an executive order issued by then-President Donald Trump during the first week of his second term, which rejected the OECD tax deal’s applicability in the US and included a warning of potential retaliatory taxes.

HM Revenue and Customs (HMRC) estimates that removing the US from full participation in the global tax framework will decrease UK tax receipts linked to the deal from an anticipated £2.2 billion to around £1.6 billion annually. Investigations into tax avoidance in 2025 are expected to involve roughly £70.1 billion, with £21 billion identified as related to international risks such as profit shifting, which the minimum tax agreement seeks to mitigate.

The global minimum tax aims to reduce incentives for large multinational corporations to relocate profits to low-tax jurisdictions, thereby limiting opportunities to reduce their overall corporate tax liabilities. Despite the concessions to the United States, the committee acknowledged that HMRC’s strategy for collecting taxes from large businesses is generally effective.

HMRC’s recently released financial accounts for 2025–2026 showed record-breaking tax revenues totaling £966.4 billion, marking the fifth consecutive year of growth. However, the government’s Comptroller and Auditor General, Gareth Davies, issued a qualified opinion on HMRC’s resource accounts, citing concerns over fraud and errors related to child benefits and research and development tax credits.

Clive Betts, deputy chairman of the Public Accounts Committee, emphasized the effectiveness of HMRC’s large business directorate, noting that for every £1 spent on staff salaries in this division, £95 in tax revenue is generated—significantly outperforming other taxpayer segments. Nonetheless, Betts criticized the lack of transparency surrounding HMRC’s efforts in tackling tax avoidance, warning that this “secrecy” could damage public confidence. He called on HMRC to increase openness and better communicate its successes to reassure the British public about its enforcement activities.