MTT and DTT have been introduced as part of the UK’s adoption of the OECD’s Pillar 2 rules. They apply for accounting periods beginning on or after 31 December 2023. The letter is the fourth in a series from HMRC intended to help businesses prepare for the introduction of the Pillar 2 taxes.  

Reporting requirements 

The letter explains that all groups in scope of MTT and DTT must register with HMRC even if there is no tax to pay. A group is within scope of the rules if it has: 

• at least one UK entity; and
• consolidated group annual revenues of 750m euros or more in at least two of the previous four accounting periods.  

The deadline for registering with HMRC is six months from the end of the first accounting period in which the group is subject to the rules.  

The group must register using HMRC’s online service. The letter explains that the group’s filing member should complete the registration and sets out the information it will need to do this. The filing member is the group’s ultimate parent unless the group nominates a different group member.  

Reporting obligations 

The group’s filing member will be HMRC’s primary point of contact for MTT and DTT. The letter lists the filing member’s reporting responsibilities and provides guidance on completing the GloBE information return (GIR) and the UK self assessment (SA) return. 

The GIR is a standardised return that HMRC says will facilitate the global administration of the Pillar 2 rules. If the GIR is filed overseas, and the group expects the foreign tax administration to provide it to HMRC, it must file an overseas return notification (ORN) in the UK. The group has 18 months to submit the GIR (or ORN) for the first accounting period it is subject to Pillar 2 taxes (eg, by 30 June 2026 for the accounting period ended 31 December 2024). 

The UK SA return will include the group’s total MTT and DTT liability as well as the liability for each UK member of the group for the period. All registered groups must submit a UK SA return, including where there is no MTT or DTT liability. The deadline for submitting the UK SA return is that same as that for the GIR or ORN. 

Other developments 

The letter also provides updates on the publication of HMRC and OECD guidance and the development of HMRC’s online service.  

On 30 April 2025, HMRC will host a webinar on the Pillar 2 taxes. A recording of the webinar will be available to view after the event on GOV.UK. 

Further information 

• Template letter provided by HMRC
• ICAEW’s TAXguide 06/23: A basic guide to pillar two