Groups that fall under the UK Pillar Two rules must register for Pillar Two top-up taxes to obtain a Pillar Two top-up tax identification number. This number is needed to file UK Pillar Two returns and to arrange payment of any top-up tax.

Who needs to register?

Registration is required in the UK for groups with both:

• At least one entity located in the UK including dormant entities.
• Consolidated group annual revenues of €750m or more in at least two out of the previous four accounting periods.

Single entities located in the UK must register if they have annual revenues of €750m or more in at least two out of the previous four accounting periods.

What Pillar Two top-up taxes do I need to register to report?

Groups with only UK entities must register for domestic top-up tax (DTT).

The registration for groups with entities both inside and outside the UK will be required for those groups to meet their UK reporting obligations for both DTT and the multinational top-up tax (MTT).

MTT will arise where a UK member of a group has direct or indirect interests in entities located outside the UK, and the group’s profits arising in that jurisdiction are taxed at below the minimum rate of 15%. DTT will arise when the group’s profits arising in the UK are taxed at below the minimum rate of 15%, ensuring any top-up tax due on UK profits is collected in the UK.

Registration is mandatory if the group meets the revenue criteria, even if no top-up tax is ultimately payable.

Which entity needs to complete the registration?

The filing member is responsible for the registration. By default, this is the ultimate parent entity (UPE), unless another group member has been formally nominated.

Although it is not a requirement for the filing member to be a UK tax resident, it may be preferable to nominate a UK resident company.

This will allow HMRC to automatically exchange the Pillar Two return with other tax authorities.

It is important to note that if the UPE nominates another group member as filing member, the nomination must be made in writing and kept on record. HMRC will not ask for proof of this nomination during registration but may request it during compliance checks.

Can RSM complete the registration?

Tax agents, including RSM, cannot complete the registration on behalf of a group. However, we can guide you through the registration process. Once the group completes the registration, it can grant its agent access to manage its Pillar Two top-up taxes.

Where can groups register?

The filing member can register via its UK Government Gateway account, using its UK Government Gateway user ID and password. If the filing member does not have a user ID, one can be created as part of the registration process.

What information is required to register?

The following information is required to complete the group registration:

• The name and registered address of the UPE.
• The name and registered address of the filing member (if this is not the UPE).
• The company registration number and Unique Taxpayer Reference (UTR) for the filing member and the UPE, if either is a UK company or limited liability partnership.
• The start and end date of the group’s accounting period.
• Whether the group only has entities in the UK or other jurisdictions.
• Contact details and preferences for one or two individuals or teams in the group.
• Postal address.

What is the deadline for registration and is there a penalty?

Groups must register within six months after the end of their first accounting period in which the Pillar Two rules apply. Penalties are calculated as a percentage of any Pillar Two top-up taxes due, with the exact percentage depending on the behaviour of the company.

Registration requirements vary across countries. We can help you understand these differences and ensure you remain globally compliant.

For support with registration and guidance on next steps, please contact our Pillar Two team, Sarah Hall and Kaila Engelsman.