Tax return deadlines in Ireland (2026)

If you earn untaxed income as a self-employed individual or from rental properties, or even if you are employed but earn an income that’s outside of your PAYE role, it’s important to complete and submit a self-assessment tax return every year, before the deadline. If you don’t, you could be subject to penalties. On this page, you’ll learn about the updated tax return deadline, what may happen if you miss the deadline and the key dates you need to know this tax year. 

If you need to do a tax return, the deadline for submitting it for the Irish tax year (1st January to 31st December) is midnight on 31 October 2026 if you’re submitting your return on paper.

If you’re submitting your return via the Revenue’s Online Service (ROS), the deadline is 18 November 2026.

If you submit your return via ROS, you will also need to pay your income tax in full by 18 November 2026 to qualify for the extension.

If you fail to submit your tax return on time, you could receive the following penalties:

• If you submit your return between 31 October 2026 and 31 December 2026, you’ll pay a surcharge that's the lesser of 5% of your tax due, up to €12,695.
• If you submit your return after 31 December 2026, you’ll pay a surcharge that's the lesser of 10% of your tax bill, up to €63,485.

The most important date in the Irish tax year if you need to complete a self-assessment tax return is 31 October 2026. By this date (or the extended ROS deadline of 18 November 2026), you must:

• Pay any preliminary tax you owe for the 2026 tax year.
• Submit your self-assessment tax return for the previous tax year (i.e., by the 2026 deadline, you will submit your tax return for 2025).
• Pay off any outstanding income tax balance from the 2025 tax year.