Key dates and updates
Registration
In-scope entities can use the Revenue Online Service (ROS) to register for Pillar Two.
The deadline for registration for in-scope entities with their first fiscal year ending in 2024 was 31 December 2025. This deadline was later extended to 28 February 2026. The deadline for all other entities is 12 months after the end of their first fiscal year.
Pay and file
The necessary IT developments required to allow return filing and payment of associated liabilities will be available on ROS in March 2026. This will enable entities to meet the 30 June 2026 deadline for pay and file.
Top-up tax information return (TIR)
The necessary IT developments required to allow the filing of the top-up tax information return will be available on ROS in March 2026. This will enable entities to meet the 30 June 2026 pay and file deadline.
Side-by-Side package
On 5 January 2026, the OECD and G20 Inclusive Framework on Base Erosion and Profit Shifting approved and adopted a Side-by-Side package for Pillar Two. The Side-by-Side package includes:
- a Side-by-Side system setting out rules to facilitate existing minimum tax regimes
- simplification measures
- changes to the treatment of substance-based tax incentives.
The package is available on the Economic Co-operation and Development’s (OECD) website.
On 12 January 2026, the European Commission published Commission Notice C/2026/253. This notice acknowledges the OECD’s Side-by-Side package and confirms its application in the context of Council Directive (EU) 2022/2523 (The Minimum Tax Directive).