Introduction

On 18 December 2025, the Irish tax authorities (Irish Revenue) published updates to Pillar Two registration guidance to include an extension of the registration deadline to 28 February 2026 for in-scope entities whose first fiscal year for Pillar Two purposes ends in 2024, in addition to other key updates regarding inactive/dormant/dissolved entities and entities with no active tax registration.

By way of background, in 2023, Ireland introduced legislation giving effect to the Organization for Economic Co-operation and Development (OECD)/G20 Inclusive Framework's Pillar Two rules under the BEPS 2.0 project.

The Pillar Two rules seek to ensure that in-scope¹ multinational enterprise (MNE) groups and large-scale domestic groups have a minimum effective tax rate of 15% in each jurisdiction of operation. This is achieved using a series of interlocking rules/taxes known as the Income Inclusion Rule (IIR) and Undertaxed Profits Rule (UTPR). Certain jurisdictions, including Ireland, have also opted to implement a Qualified Domestic Top Up Tax² (QDTT).

The Pillar Two rules require in-scope groups to comply with a series of registration, filing and payment obligations. To enable taxpayers to satisfy these obligations, Irish Revenue launched the Pillar Two Hub and registration platform on 14 August 2025,³ which included Tax and Duty Manual Part 04A-01-01A (Guidance on Pillar Two — Registration).

Details on the updates published on 18 December 2025 are set out below.

Extension of registration deadline

Entities⁴ located in Ireland that are within the scope of the rules must register for the relevant Pillar Two taxes (i.e., IIR, UTPR, QDTT) within 12 months from the end of the first fiscal year for which the entity is subject to the relevant tax.

Entities must also register for the Top-up tax information return (TIR) (also known as the GloBE Information Return (GIR))⁵ at the same time, regardless of whether they are the GIR filing entity, to facilitate either the filing of the GIR or the notification of filer where another entity will file the GIR.

Irish Revenue extended this deadline to 28 February 2026 where a registration notification date arises on or before 31 December 2025. Entities with a fiscal year ending on or before 31 December 2024, which are subject to the IIR and/or QDTT for 2024, can therefore avail of the extension to register by 28 February 2026.

At this time, the extension is only provided for 2024 fiscal year-ends. It does not apply therefore to 2025 fiscal year-ends, for example, January/February 2025 year-ends where the Pillar Two registration deadline may be before 28 February 2026.

Entities must also provide the following details in advance of the (extended) registration deadline: (1) whether a GIR will be filed in Ireland or whether the GIR filing obligation will be met by a designated filing entity (DFE) in another jurisdiction and (2) whether the registering entity is electing to become a member of a QDTT group and/or a UTPR Group, and if so, whether it is appointed as the QDTT/UTPR Group Filer.⁶

Registration should be completed via Irish Revenue's Revenue Online Service (ROS). Failure to register could lead to a penalty of €10k.

Entities that qualify for the Transitional Country by Country Safe Harbour (TCSH) are also required to register for Pillar Two taxes.

Once registered, entities must notify Irish Revenue of any change in the information provided, including if the entity ceases to be subject to the relevant tax, within 12 months of the end of the fiscal year in which the change occurred.

New Irish Revenue administrative practice for inactive/dormant entities

Irish Revenue is prepared to accept, as an administrative practice, that inactive/dormant entities are not required to register for Pillar Two purposes in Ireland where the entity (1) is incorporated and never traded or held any assets, or (2) is an entity that had income and/or assets in the past and is now inactive but remains within the group.

The updated guidance sets out the process to remove the obligation of the inactive/dormant entity from registering for Pillar Two in advance of the extended registration deadline.

The MNE Group must nominate an entity to provide Irish Revenue with the following:

• Details of the inactive or dormant entities in the group, including the name, Company Registration Number (CRO) number and Tax Identification Number (TIN), if applicable
• Confirmation that these entities had no qualifying income for the purposes of Pillar Two and held no assets that would give rise to qualifying income for the purposes of Pillar Two throughout the relevant fiscal year
• Confirmation that these entities will not have any liability to IIR top-up tax, UTPR top-up tax or QDTT for the relevant fiscal year
• Confirmation that the details of the entities will be included on the GIR filed on behalf of the group
• Confirmation that where circumstances change, the group will notify Irish Revenue within 12 months of the change and arrange registration for the appropriate tax

This information must be submitted electronically (via MyEnquiries) selecting the appropriate options from the dropdown menu.

Where the only entity in Ireland is dormant (i.e., there are no other constituent entities in the group in Ireland) the five items listed above should be submitted to Irish Revenue by email at pillartwo@revenue.ie.

New Irish Revenue administrative practice for dissolved entities

Irish Revenue also provided guidance on dissolved entities that may have been in-scope of the rules prior to the date of dissolution.

As dissolved entities cannot complete the registration process, it is expected that details of the dissolved in-scope entity will be included in the GIR filed on behalf of the MNE Group.

New Irish Revenue administrative practice for entities with no active tax registration

Irish Revenue suggests that in-scope corporate entities that currently do not have access to the registration portal for Pillar Two (i.e., entities that have not previously registered for tax in Ireland), first register for Corporation Tax to enable access to the Pillar Two registration portal.

Irish Revenue clarified that this process by itself does not create an obligation to file a return under Corporation Tax where one does not exist under Irish Tax legislation.

In cases where these entities are not required to file a Corporation Tax return, they can de-register for Corporation Tax once the Pillar Two registration is complete.

Payment and filing obligations

There has been no change to these deadlines for the relevant Pillar Two returns (i.e., QDTT/IIR/UTPR returns and self-assessments) that are due for filing, along with any payments due, within 15 months from the end of the fiscal year (extended to 18 months where the fiscal year is a Transition Year).⁷

The GIR (or notification of filer) must also be filed within 15 months of the end of the fiscal year (extended to 18 months if the fiscal year is a Transition Year). If there are multiple Irish-located entities, a designated local entity (DLE)  may be appointed to file a GIR with Irish Revenue on behalf of all the Irish entities or prepare and deliver the notification of filer to Irish Revenue with details of the entity filing the GIR.

Next steps

In-scope groups should assess and identify the Pillar Two registration requirements for each of their Irish entities. This is particularly relevant for taxpayers with fiscal years ending after 31 December 2024 who are still required to register within 12 months (this could be as early as 1 January 2026 for those with a fiscal year ending on 1 January 2025).

Where there are multiple Irish entities in a group, consideration should be given as to the appropriateness of forming a QDTT group/UTPR group and the relevant filing entity for the group in advance of the registration deadlines. Groups also need to consider which entity will file the GIR, which should include an analysis of GIR MCAA coverage and how this information will be exchanged.

Affected taxpayers should contact their tax advisors to discuss their Pillar Two registration and compliance obligations ahead of the relevant deadline.