Irish Revenue opens Pillar II registration

On 15 August 2025, Irish Revenue officially launched its Pillar II registration portal, marking a significant milestone in Ireland’s implementation of the OECD’s global minimum tax framework. This move affects multinational enterprise (MNE) groups and large-scale domestic entities operating in Ireland that fall within the scope of the Pillar II rules. Here's what impacted taxpayers need to know.

Who needs to register?

Entities must register with Irish Revenue if they are subject to any of the following Pillar II taxes:

• Income Inclusion Rule (IIR)
• Undertaxed Profits Rule (UTPR)
• Qualified Domestic Top-up Tax (QDTT)

This includes:

• Irish constituent entities of in-scope MNE groups.
• Ultimate parent entities (UPEs) located in Ireland.
• Standalone entities or members of large-scale domestic groups that meet the revenue thresholds and other criteria.

It is important to note that registration is required regardless of whether the entity has a Pillar II tax liability.

What information is required for registration?

Registration must be completed via the Revenue Online Service (ROS). Entities will need to provide:

• Confirmation of applicable tax obligations (IIR, UTPR, QDTT).
• Entity type (UPE or constituent entity).
• Group structure (e.g., multi-parented MNE or domestic group).
• First fiscal year in scope.
• Filing responsibilities (whether the entity will file or designate another filer).
• Elections to join UTPR or QDTT groups and identification of group filers.

Currently, registration is only possible on an entity-by-entity basis, though Revenue may issue further guidance on group registration options. 

Deadline for registration

Entities must register within 12 months of the end of the first fiscal year in which they come within scope of Pillar II. For most entities with a fiscal year ending 31 December 2024, the registration deadline is 31 December 2025.

Penalties for late registration

Failure to register by the deadline will result in a penalty of €10,000 per entity. This underscores the importance of early engagement and planning to ensure compliance.

Next steps for taxpayers

Impacted groups should:

• Review their group structure and determine if they are in scope.
• Begin gathering the required registration information.
• Monitor Revenue updates for any changes to the registration process.
• Consider designating a QDTT or UTPR group filer where applicable.

Early action will help avoid penalties and ensure smooth compliance with Ireland’s Pillar II obligations.