DEADLINES14 December 2025 · 5 min read
Ireland Tax Calendar 2026: Key Dates & Deadlines
The Irish tax dates that actually matter in 2026 — in one place, in plain terms, so nothing catches you out.
31 January 2026
Deadline to pay CGT on any disposals in December 2025.
31 March 2026
Last day to file the 2025 Local Property Tax return.
31 October 2026
The big one. Paper Form 11 deadline for 2025 self-assessment. Also: pay 2025 income tax balance, preliminary 2026 tax, and file CAT returns for the year to 31 August 2026.
Mid-November 2026
ROS-extended Form 11 deadline (typically ~14 November — Revenue confirms the exact date each year). Same date extends the AVC-into-prior-year window.
15 December 2026
Pay CGT on any disposals between January and November 2026.
Rolling all year
The 4-year refund window — 2022, 2023, 2024 and 2025 are all still claimable throughout 2026.