Business Tax Briefing

Government confirms intention to hold ‘Tax Update’ in early 2026

At Budget 2025, the government stated that it would announce “further changes to simplify and improve tax and customs administration at a Tax Update in early 2026.” At an appearance before the House of Lords Finance Bill Sub-Committee on 8 December 2025, Exchequer Secretary Dan Tomlinson MP provided further detail, confirming that he intends to take a similar approach to his predecessor, and publish a range of policy consultations in the new year, potentially around the time of a Spring Statement. In April 2025, previous Exchequer Secretary James Murray MP published a package of technical tax policy announcements and supporting documents titled Tax Update Spring 2025: Simplification, Administration, and Reform (or TUSAR).

HMRC publish interim guidance on changes to capital gains anti-avoidance provisions

HMRC have published a new appendix to their Capital Gains Manual (CG-APP19) setting out provisional guidance on changes, announced at Budget 2025, and which took immediate effect on 26 November 2025. The appendix also sets out HMRC’s approach to statutory clearances, including cases where subsequent changes are made to a transaction, or where a clearance was submitted prior to 26 November 2025, but no decision has yet been received.

HMRC publish guidance on share reorganisations and non-UK mergers

HMRC have also published a new page in their Capital Gains Manual (CG52502) setting out their view on how certain corporate reorganisation provisions might apply in the context of international mergers. A common issue is whether the conditions of section 135 Taxation of Chargeable Gains Act 1992 (TCGA 1992) are met where there is not a simple exchange of shares (e.g. because another step or company is involved in a merger). According to the new guidance, HMRC’s view is that section 135 TCGA 1992 is capable of applying (subject to meeting the necessary conditions, including new anti-avoidance provisions covered above) where the issuing company acquires the full benefit of the shares previously held by the original shareholders and where the overall effect of the transaction is the same as if those shares had been acquired directly, as would happen under UK company law. The guidance notes that a similar approach is taken where section 136 is in point.

HMRC publish draft guidance on advance tax certainty for major projects service

On 10 December 2025, HMRC published draft guidance on the government’s new advance tax certainty service, due to launch in July 2026. The new service, trailed in the Corporate Tax Roadmap and announced at Spring Statement 2025, is intended to provide binding certainty on how tax rules will apply to major investment projects in the UK, before significant investment takes place. Eligible projects are broadly those involving in-scope expenditure of at least £1bn over their lifetime. The service will cover corporation tax, VAT, stamp taxes, PAYE, and the Construction Industry Scheme.

The draft guidance includes details of how the scheme works, who can apply, the taxes covered and the financial threshold. HMRC state that the guidance is subject to change, in line with the parliamentary process of the Finance Bill, and that it will be finalised ahead of the formal launch of the service. HMRC note that the draft guidance reflects the position during the first year, e.g. the process section sets out how HMRC will manage the process in the first year of the service in the event that interest from businesses exceeds HMRC’s available capacity. The guidance will be updated as the service progresses.

UK treaty ratification progress update: Andorra, Peru, Portugal and Romania

The statutory instruments bringing into effect the UK’s new double tax treaties with Andorra, Peru, Portugal and Romania were made on 10 December 2025. This marks the final step in the UK ratification process for each of these treaties. Once both parties to a treaty have notified each other that their domestic ratification procedures have been completed, that treaty will then enter into force and have effect in line with the provisions in its entry into force article. It is expected that the relevant GOV.UK page (Andorra, Peru, Portugal and Romania) will be updated once each treaty has entered into force.

OECD releases tax revenue statistics report

On 9 December 2025, the OECD released the latest in its annual series of statistical reports Revenue Statistics 2025. The report provides internationally comparative data on tax levels and tax structures in OECD member jurisdictions. The report finds that the provisional tax-to-GDP ratio for the UK decreased from 35.0% to 34.4% between 2023 and 2024, while the OECD-average ratio increased from 33.7% to 34.1% over the same period. Overall tax revenues increased as a share of GDP in 2024 in 22 of the 36 OECD countries surveyed, declined in 13 countries, and remained at the same level in one. Among the 36 countries for which preliminary data is available, tax-to-GDP ratios ranged from 18.3% (Mexico) to 45.2% (Denmark) in 2024.

EMEA Dbriefs webcasts

The EMEA Dbriefs programme is taking a brief break now for the holiday period. If you want to be informed about upcoming webcasts throughout 2026, please subscribe to receive our mailings. In the meantime, you can catch up on demand with any recent webcasts you may have missed, including: Off payroll workforce tax and legal risk; Exit readiness – key tax priorities to be aware of in advance of a transaction; Should payroll be the only constant in a world of change? and Achieving practical transfer pricing certainty through ICAP: Insights and discussion with HMRC.

Deloitte’s Business Tax Briefing is taking a break for the holiday period. The next edition will be published in the new year.