Corporation Tax

In keeping with the government’s Corporation Tax Roadmap, which was part of their election manifesto, the current rates (of 19% and 25%) continue to remain unchanged.

There were a number of changes contained within the detailed Budget notes, primarily of an administrative nature and include the following:

  • The government will double the penalty for companies submitting a Corporation Tax Return late from 1 April 2026.
  • The government will consult in early 2026 on delivery timescales and enforcement for prescribing the content and tagging of the Corporation Tax computation.
  • The government will publish a consultation in early 2026 to explore introducing new requirements to report transactions (primarily loans) between close companies and their shareholders to HMRC.
  • The government will legislate in Finance Bill 2025-26 to simplify taxation of related party transactions, non-resident companies trading in the UK, and profits diverted from the UK, for chargeable periods beginning on or after 1 January 2026.
  • Targeted research and development (R&D) advance assurance service. The government will pilot a targeted advance assurance service from Spring 2026, enabling small and medium-sized enterprises to gain clarity on key aspects of their R&D tax relief claims before submitting to HMRC. The government is also publishing a summary of responses to the advance clearance consultation.
  • Advance Corporation Tax (ACT) reform and consultation. The government will legislate through statutory instrument to repeal the shadow ACT rules with effect from 1 April 2026, and will consult on the future of the remaining ACT regime in early 2026.
  • Corporate Interest Restriction (CIR). The government will legislate in Finance Bill 2025-26 to simplify administration in relation to reporting companies under CIR. Most of the changes take effect for periods ending on or after 31 March 2026.
  • Corporate Interest Restriction (CIR). The government will also legislate in Finance Bill 2025-26 to make technical amendments to CIR in respect of relief for certain capital expenditure. The changes take effect for periods ending on or after 31 December 2021. 

Please click here to go back to our full Autumn Budget 2025 analysis.