From 1 June 2026, potential applicants to HMRC’s new Advance Tax Certainty Service (ATCS) are able to submit ‘expressions of interest’, ahead of the full launch of the ATCS on 1 July 2026. The service will provide a route to certainty on the taxation of very large UK investment projects. HMRC have now published their final guidance in the form of an ATCS manual which outlines the scope, process and eligibility requirements of the ATCS. The manual largely follows draft guidance which has previously been published and was discussed in our earlier article. The manual does, however, add further information on how a ‘low-risk’ view may be obtained on the potential application, to the investment project, of the unallowable purpose rules in the loan relationships and derivative contracts regimes.
HMRC manual published on the Advance Tax Certainty Service
HMRC manual published on Mandatory Tax Adviser Registration
Finance Act 2026 introduces a new requirement for tax advisers to register with HMRC which, as explained in our recent article, will potentially apply quite widely; capturing some in-house tax teams, law firms, financial institutions, asset managers and family offices. The registration process opened on 18 May 2026 and is currently open for “New tax advisers, or those interacting with HMRC without an agent services account (ASA), Self Assessment or Corporation Tax account”. On 1 June 2026, HMRC published final guidance in the form of a new manual. It provides some useful additional information not covered in earlier announcements but there are still some points of detail where further clarity is needed.
OECD publishes consolidated commentary to GloBE model rules
The Global Anti-Base Erosion (GloBE) rules ensure large multinational enterprise groups (MNE groups) pay a minimum level of tax on their income arising in each of the jurisdictions where they operate. The commentary to the GloBE Rules was originally released by the OECD Inclusive Framework on Base Erosion and Profit Shifting (BEPS) in March 2022. It explains the intended outcomes under the rules, clarifies the meaning of certain terms and illustrates the application of the rules to certain fact patterns. Since the commentary was first released, there have been various pieces of additional administrative guidance approved by the Inclusive Framework which have now been incorporated into consolidated commentary released by the OECD on 28 May 2026. This consolidated commentary doesn’t include any new content – it incorporates agreed administrative guidance released from March 2022 to January 2026 and is the third time the OECD has published consolidated text. It aims to provide “tax administrations and taxpayers with comprehensive guidance on the interpretation and application of the GloBE Rules in order to promote a consistent and common interpretation and application of those that will facilitate co-ordinated outcomes”.
Consultation published on guaranteed minimum pension conversion provisions
On 8 June 2026, HMRC published draft regulations that will amend Finance Act 2004 for calculating pension input amounts for annual allowance purposes following guaranteed minimum pension conversion. The proposed changes are not a result of any amendment to tax policy. Instead, the aim is to amend the tax rules so the same tax outcome (including preserving long standing protections from annual allowance tax charges for deferred members) is available regardless of the method chosen to equalise benefits. HMRC have requested comments on the draft legislation by 13 July 2026.
Updated guidance published on UK-India Double Contribution Convention
The UK and India signed a social security Double Contribution Convention in February this year, which is expected to come into force this summer. In advance of this, HMRC recently published an updated National Insurance manual which provides guidance and clarifications. This guidance is very helpful for employers who currently have employees on assignment to or from India, or are expecting to send employees on assignment in the future. Our Flash Alert covers the key points of HMRC’s updated guidance.