Ireland's Pillar Two registration obligations

Irish Revenue opened the online registration portal for Pillar Two registration on 15 August 2025. The registration must be completed via the Revenue Online System (ROS).

Which entities are required to register?

Irish Constituent Entities that are within scope of the Pillar 2 rules must file a one-time registration with Irish Revenue within 12 months of the end of the first Fiscal Year to which the Pillar 2 rules apply to the MNE (i.e. fiscal years beginning on or after 31 December 2023).

Importantly, registration is required for groups within scope even if no Top-up Taxes are due.

The registration applies to entities which are within the scope of (i) the Income Inclusion Rule (IIR), (ii) the Undertaxed Profits Rule (UTPR), and/or (iii) the domestic top-up tax (QDTT) in Ireland.

31 December 2025 deadline deferral

Revenue published e-Brief No. 244/25 announcing an extension to the Pillar Two registration deadline for groups with a fiscal year of 1 January to 31 December 2024, who were due to register by 31 December.

The revised deadline for in scope entities is now 28 February 2026. For groups with a non-31 December fiscal year-end, the normal 12-month deadline for registration remains.

The extension has been granted to allow certain technical fixes to be made to Revenue’s Online System to ensure that groups with complex fact patterns can successfully navigate the registration process. This is a very welcome development for groups with certain fact patterns that have experienced difficulties accurately completing the step-by-step registration process.

In addition, Irish Revenue have provided helpful clarifications for groups seeking to register the following entities:

Dissolved entities

Should not be required to submit an entity-specific registration, provided details relating to that entity are included in the GloBE Information Return submitted by the MNE Group.
Inactive / dormant entities

An entity-specific registration should not be required where certain conditions are met. However, in order to avail of this concession, a submission should be made to Irish Revenue via MyEnquiries. Details relating to the inactive / dormant entity must be included in the GloBE Information Return submitted by the MNE Group.

The above entities will not impact the group’s ability to form an Irish QDTT / UTPR group.

Entities with no active tax registration

At present, Pillar Two taxes cannot be the sole tax head registration for an entity. The entity will need to register initially for corporation/ income tax. However, this registration can subsequently be de-activated and a corporation or income tax return would not need to be submitted.

Overall, this latest announcement from Irish Revenue is a positive development, providing additional time for groups to ensure compliance with Irish Pillar Two registration requirements. Further guidance is expected in early 2026 to address registration for entities in liquidation, joint ventures, mergers, and those transitioning between MNE groups.

Process for filing

The process for registering is online via the Revenue Online System and it is possible for an agent, such as KPMG, to register on behalf of the entity.

Where KPMG is not the registered tax agent, then it may be necessary to obtain authorisation from the company.

What information needs to be reported for the initial notification?

To complete the online form, following information will be required:

The name of the Entity
TIN (tax identification number) of the Entity
Tax/Taxes for which the Entity is registering (IIR, UTPR, or QDMTT)
Details in respect of the UPE (Name, Location, TIN)
The first Fiscal Year to which the Irish Pillar 2 rules apply to the Entity
Information in respect of the Designated Filing Entity of the MNE group (if applicable)
Information in respect of the Designated Local Entity
Information in respect of the QDTT group (if applicable)
Information in respect of the UTPR group (if applicable)

A detailed Information Request List can be provided on request.

Practical considerations

Irish Revenue intends to directly contact entities who they believe are within the scope of Pillar 2 in relation to the registration requirements. This will be carried out on a phased basis, starting with groups with an Irish Ultimate Parent Entity. However, it’s not necessary to await this communication before completing the registration process.
An entity must notify the Irish Revenue Commissioners of any change to the information provided in the notice within 12 months of the end of the fiscal year in which the change occurred.
Where an entity is no longer subject to the Irish domestic top-up tax, they must cease their registration. The entity must notify Revenue within 12 months of the end of the first fiscal year it is no longer subject to the top-up tax.
Where an entity fails to submit the required registration or fails to update the registration details or de-register, there is a potential penalty of €10,000.

Tax Return filings

The first Pillar 2 tax returns and payment obligations will be due by 30 June 2026 (i.e. 18 months after the end of the first fiscal year) and Irish Revenue confirmed that the new online tax return system should be available in early 2026.