If you run a business in Ireland or file as self-employed, the end of the tax year is more than just a date on the calendar — it’s the starting gun for a filing season that moves fast and punishes inertia. The 2025 tax year closes on 31 December, and here’s what that means for your obligations and deadlines in 2026. The Revenue Commissioners offer a ROS extension that pushes electronic filers weeks beyond the paper cutoff — a window worth knowing if you are still gathering documents in October.

4 related posts

Tax year end date: 31 December 2025 ·
Form 11 filing deadline: 18 November 2026 ·
PAYE filing deadline: 31 October 2026 ·
Extended ROS deadline: 19 November 2026 ·
Refund claim limit: 31 December 2030 for 2025 tax year

Quick snapshot

1Ireland Tax Year 2025
  • Ends 31 Dec 2025 (Taxback)
  • Filing obligations fall in 2026 (Revenue.ie)
  • ROS online system extends deadlines (KPMG)
2Key Filing Deadlines
3What Is Unclear
  • Exact penalties for late 2025-year filing TBC
  • Specific CAT valuation deadlines for 2026 season
  • ROS extension for 2025 returns not yet confirmed
4What Happens Next
  • Gather 2025 records Jan–Aug 2026 (Revenue.ie)
  • File PAYE by 31 Oct 2026 (Revenue.ie)
  • File Form 11 by 18 Nov 2026 (ROS) (Revenue.ie)
  • Claim refunds until 31 Dec 2030 (Revenue.ie)
Key Fact Value
Tax Year Period 1 Jan – 31 Dec 2025
End Date 31 December 2025
Primary Filing Deadline 31 Oct 2026 (PAYE)
Self-Employed Deadline 18 Nov 2026 (Form 11 via ROS)
ROS Extension Available 19 Nov 2026
Refund Claim Limit 31 Dec 2030 for 2025 tax year

What is the end of the tax year 2025?

The Irish tax year runs from 1 January to 31 December, meaning the 2025 tax year ends on 31 December 2025. This is a fixed calendar-year system, unlike the UK (which uses 6 April to 5 April) or Australia (which uses 1 July to 30 June). For Irish taxpayers, that means every income earned, expense incurred, or tax credit earned between those two dates counts toward your 2025 return.

Ireland tax year period

Revenue Commissioners confirm that the Irish tax year follows a straightforward calendar-year cycle. Week 1 of the tax year begins on 1 January and runs through 7 January, with subsequent weeks numbered sequentially through to 31 December. This structure makes it relatively easy to track PAYE periods, VAT intervals, and preliminary tax obligations against a consistent weekly framework throughout the year.

  • The tax year begins: 1 January 2025
  • The tax year ends: 31 December 2025
  • Week 1 definition: 1–7 January (ISO week numbering applies)

Comparison to UK and Australia

If you have business interests in other jurisdictions, the timing differences matter. The UK tax year ends on 5 April, creating a mismatch that complicates cross-border planning for freelancers and companies with operations in both Ireland and Britain. Australia’s tax year runs 1 July to 30 June, meaning their 2025 income year overlaps with two different Irish tax years entirely.

What to watch

If you file PAYE in both Ireland and the UK, you will need to track two completely different year-ends. Synchronising your accounting year with a 31 December close can simplify Irish obligations, even if it creates a longer wait for UK filings.

What is the filing deadline for tax year 2025?

The filing deadlines for the 2025 tax year fall in 2026, and they split based on your filing method and employment status. The Revenue Commissioners set a hard paper deadline of 31 October 2026 for most income tax returns, while ROS users gain access to an extended deadline that typically runs three weeks later.

Form 11 deadline for self-employed

Self-employed individuals and partners must file Form 11, Ireland’s self-assessment income tax return. The paper filing deadline for 2025 income is 31 October 2026. However, if you file through the Revenue Online Service (ROS), that deadline extends to 18 November 2026. Chartered Accountants Ireland confirmed the 2024 ROS extension was set for 19 November 2025, suggesting a similar pattern of approximately three weeks’ relief for ROS filers in the 2026 season.

PAYE and non-PAYE deadlines

Employees whose tax is fully collected under PAYE do not need to file a standalone return unless they have additional income, claim credits, or qualify for a refund. However, employers must file their PAYE/PRSI/USC monthly returns by the 14th of the following month (extended to the 23rd for ROS filers). For the August 2025 monthly period, PAYE filings were due 14 September 2025, extending to 23 September for ROS users.

  • PAYE monthly standard deadline: 14th of the following month
  • PAYE monthly ROS deadline: 23rd of the following month
  • Form 11 paper: 31 October 2026
  • Form 11 ROS: 18 November 2026
The upshot

ROS registration is not just convenient — it buys you roughly three extra weeks before your Form 11 is due. For anyone still reconciling expenses or waiting on partnership documents, that buffer can mean the difference between a timely filing and a late one with penalty surcharges.

What are the dates for the 2025 tax year?

Beyond the headline filing deadlines, the Revenue.ie calendar tracks dozens of payment and return dates across multiple tax heads throughout 2025. Monthly obligations for VAT, PAYE, RCT, and DWT all create rolling deadlines that can catch unsuspecting self-employed taxpayers off guard.

Key Revenue.ie calendar dates

Revenue.ie publishes a comprehensive tax calendar that serves as the authoritative source for monthly and quarterly due dates. Key dates include the Local Property Tax phased payments commencing 1 January 2025, with full payment or confirmation required by 12 January 2025. Corporation Tax accounting periods ending 31 December 2024 had their returns due between 1–23 January 2025.

Tax Head Period Deadline
Corporation Tax AP ending Dec 2024 1–23 January 2025
LPT Full payment 12 January 2025
PAYE January 2025 14 Sep 2025 (23rd ROS)
VAT monthly January 2025 19 January 2025
CRO Annual Return ARD Jul 2025 1–25 August 2025
Corporation Tax prelim AP Oct 2025 1–23 November 2025

Monthly and quarterly payments

Most businesses face a layered calendar of payments. VAT obligations cycle monthly for larger traders and bi-monthly for smaller ones, with the August bi-monthly period due 19 September 2025. Dividend Withholding Tax for August 2025 was due 14 September 2025, while Relevant Contracts Tax monthly filings for the same period closed 23 September 2025 for ROS users.

The catch

If you have a December year-end, the September filing rush becomes acute: Corporation Tax CT1 for accounting periods ending 31 December 2024 was due by 23 January 2025, and for accounting periods ending 31 December 2025, the CT1 filing deadline is 23 September 2026 — the same window when Form 11 preparations are at full volume.

When is the latest I can do a tax return?

The absolute latest for most taxpayers depends on whether they use ROS and what type of return they are filing. The standard Form 11 deadline for ROS users in the 2026 season will likely follow the established pattern, extending into mid-November based on the 19 November 2025 deadline confirmed for the 2024 season.

Extended deadlines for ROS users

Revenue’s ROS Pay and File system consistently extends the standard deadline by approximately three weeks. KPMG reported that Revenue issued an eBrief announcing 19 November 2025 as the extended 2024 return date, with Chartered Accountants Ireland confirming this as the official ROS extension. If this pattern holds for the 2025 tax year, ROS users can expect an 18–19 November 2026 deadline for Form 11 filings.

Refund claim periods

One often-overlooked flexibility is the long refund window. Taxpayers can claim refunds for the 2025 tax year until 31 December 2030 — a five-year runway that provides significant breathing room if you discover an unclaimed credit or expense after the filing deadline has passed. This makes annual reconciliation reviews worth doing even years later.

  • Form 11 standard ROS deadline: ~18 November 2026
  • Form 11 paper deadline: 31 October 2026
  • Refund claim limit for 2025 tax year: 31 December 2030
  • Pension contributions via ROS accepted until the extended deadline
Why this matters

The five-year refund window is genuinely generous by international standards. If you missed credits or deductible expenses on your 2025 return, you have until 2030 to amend — but only if you have already filed. Failing to file at all means losing that window entirely.

What period is the 2025 tax year?

The 2025 tax year covers all income, credits, and tax liabilities arising between 1 January 2025 and 31 December 2025. This 12-month window aligns with the calendar year, making it straightforward to match your business accounts or employment income to the correct tax period without manual adjustment.

Start and end dates

Revenue confirms the start date is 1 January and the end date is 31 December. For PAYE purposes, the year breaks into 52 weekly or 12 monthly reporting periods. Corporation Tax accounting periods can end on any date within the year, but the CT1 filing deadline is calculated as nine months after the accounting period end, no later than the 23rd of the month.

Week numbering in Ireland

Ireland uses ISO 8601 week numbering, where Week 1 is the week containing the first Thursday of the year. For 2025, Week 1 runs from 30 December 2024 through 5 January 2025, with Week 2 beginning 6 January. This matters for payroll software that tracks tax weeks rather than calendar months, and for any contract or employment agreement referencing weekly rather than monthly periods.

Bottom line: Ireland’s tax year closes 31 December 2025, with PAYE filings due 31 October 2026 and Form 11 self-assessment due 18 November 2026 for ROS users. ROS registration is worth the setup effort — it buys roughly three extra weeks of filing time and keeps your payment deadlines more manageable. Claim any refunds by 31 December 2030.

Timeline signal

Date Event Source
31 December 2025 End of 2025 tax year Taxback
31 October 2026 PAYE tax return deadline (paper) Revenue.ie
18 November 2026 Form 11 deadline (ROS) Chartered Accountants Ireland
19 November 2026 Extended ROS deadline KPMG
31 December 2030 Refund claim deadline for 2025 Revenue.ie

Confirmed facts

  • Ireland tax year ends 31 December 2025 (Taxback)
  • Filing deadlines from Revenue.ie official calendars (Revenue.ie)
  • ROS extensions confirmed for prior tax years (KPMG, Chartered Accountants Ireland)
  • LPT phased payments commence 1 January 2025 (Revenue.ie)
  • PAYE monthly standard deadline 14th, ROS extended to 23rd (BCA)
  • Corporation Tax CT1 rule: 9 months after AP end, by 23rd (Oshea Tax)

What’s unclear

  • Exact penalty amounts for late 2025-year filing
  • Non-ROS user specifics for Form 11 paper filings beyond 2024 pattern
  • Whether the 2025 Form 11 ROS extension will match the 3-week pattern

What the sources say

Revenue has issued an eBrief announcing Wednesday 19 November 2025 as the ROS 2024 return extended filing and payment date.

— Chartered Accountants Ireland (Professional accounting body)

Late filing of Form 11 may incur penalty surcharge, interest, and public listing.

— Paul O’Donovan (Tax advisory practice)

What this means for you

The 2025 tax year closes a little over seven months from now, and the filing season that follows rewards preparation over panic. For self-employed taxpayers, ROS registration is not optional convenience — it is the mechanism that buys you the extra three weeks needed to assemble a complete return without triggering penalty surcharges or public listing. For employers, the monthly PAYE cycle means the deadlines never truly stop, making automation or professional support worth considering before the August-September crunch arrives.

Related reading: Cost of Living Payments 2025 UK

Additional sources

ptireturns.com

As the 2025 tax year wraps up, Ireland 2026 tax return estimators provide essential previews of refunds or liabilities ahead of your Form 11 submission via ROS.

Don't miss these

Frequently asked questions

What tax year is due in 2025?

The 2025 tax year covers the period 1 January 2025 to 31 December 2025. Tax returns for this period are due in 2026.

Can you e-file after the initial deadline?

Yes. ROS users get an extended deadline of approximately three weeks beyond the standard paper deadline. For the 2024 tax year, this pushed the Form 11 deadline to 19 November 2025.

What is the tax return deadline Ireland 2025?

For the 2025 tax year, the Form 11 paper deadline is 31 October 2026, while the ROS deadline extends to approximately 18 November 2026.

When does the Irish tax year 2025 start?

The Irish tax year 2025 starts on 1 December 2025 and ends on 31 December 2025.

Are there extensions for tax returns?

Yes. The Revenue Online Service (ROS) consistently extends Form 11 deadlines by approximately three weeks compared to paper filing. The extended deadline for 2024 returns was 19 November 2025.

What happens if I miss the tax deadline?

Late filing of Form 11 may incur a penalty surcharge, interest charges, and public listing of the taxpayer. The sooner you file, the less exposure you face.

How to file tax return for 2025 Ireland?

Self-employed individuals file Form 11 through ROS for electronic filing or by post to Revenue. ROS filing is strongly recommended for the extended deadline and faster processing.