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This guide covers every major Irish tax deadline for 2026 — income tax (Form 11), corporation tax (CT1), VAT (VAT3), PAYE, capital gains tax (CGT), capital acquisitions tax (CAT), and CRO annual returns — and is written for SME owners, sole traders, proprietary directors, and startup founders managing their own compliance.
Income Tax (Form 11) — 31 October & 18 November 2026
If you’re self-employed, a sole trader, or a proprietary director, or you have any income outside of PAYE, your income tax return for the 2025 tax year is due in 2026.
| Filing Method | Deadline |
| Paper filing | 31-Oct-26 |
| ROS (online) — file AND pay | 18-Nov-26 |
The 18 November ROS extended deadline was confirmed by Revenue in eBrief No. 034/26. The extension is not automatic — it only applies if both your return and your payment are completed through ROS (Revenue Online Service). If you file through ROS but pay by cheque or bank transfer outside ROS, the 31 October deadline applies.
This is the most common mistake Irish SME owners make: assuming the November extension is theirs by default.
What you’re paying on 31 October / 18 November:
- The balance of your 2025 income tax liability
- Your 2026 preliminary income tax — either 90% of your estimated 2026 liability, 100% of your 2025 final liability, or 105% of your 2024 liability (the 105% option is only available by direct debit)
Late filing surcharges (Section 1077E TCA 1997):
- Filed within 2 months of the deadline: 5% surcharge, capped at €12,695
- Filed more than 2 months late: 10% surcharge, capped at €63,485
- Interest on unpaid tax: 0.0219% per day (approximately 8% per annum)
If you need support managing your self-assessment tax return in Ireland, having your records organised by mid-October — not late October — gives your accountant or outsourced partner enough time to file comfortably before either deadline.
Corporation Tax (CT1) — 23 September 2026
For Irish limited companies with a 31 December 2025 accounting year-end, your Corporation Tax 1 (CT1) return must be filed through ROS by 23 September 2026.
Corporation tax returns are due by the 23rd day of the ninth month after your accounting period ends. Companies with March, June, or September year-ends will have different CT1 deadlines across the year—the December year-end is simply the most common.
Preliminary tax payments for the December 2025 year-end:
| Company Type | Payment | Deadline |
| Small companies (prior year CT liability ≤ €200,000) | One payment | 23-Nov-26 |
| Large companies | First instalment (45–50% of liability) | 23-Jun-26 |
| Large companies | Second instalment | 23-Nov-26 |
iXBRL financial statements must be filed alongside your CT1. Revenue allows up to three months after the CT1 deadline for iXBRL, but your CT1 is not considered complete until both are filed — file them together to avoid complications.
Consequences of missing the CT1 deadline:
- 5% surcharge (within 2 months); 10% surcharge (beyond 2 months) — same caps as income tax
- Loss relief restriction of 25–50% — meaning losses you carry forward or back are partially disallowed
- Interest at 0.0219% per day on unpaid corporation tax
If your company uses year-end accounts in Ireland to prepare its financials, those accounts feed directly into the CT1 – late accounts mean a late return.
VAT Deadlines 2026 — Bi-Monthly on the 23rd
Most VAT-registered businesses in Ireland file bi-monthly VAT3 returns through ROS. Returns and payments are due by the 23rd of the month following the end of each two months.
| VAT Period | ROS Filing Deadline |
| January – February 2026 | 23-Mar-26 |
| March – April 2026 | 23-May-26 |
| May – June 2026 | 23-Jul-26 |
| July – August 2026 | 23-Sep-26 |
| September – October 2026 | 23-Nov-26 |
| November – December 2026 | 23-Jan-27 |
Paper filers are subject to an earlier deadline of the 19th of the month. The vast majority of Irish businesses are now filing through ROS.
Penalties for late VAT returns:
- Fixed penalty of €4,000 per late VAT3 return
- Interest on late payment: 0.0274% per day (approximately 10% per annum)
Return of Trading Details (RTD): Your RTD is due with your final VAT return of the year. An outstanding RTD will block your Revenue Tax Clearance Certificate, which you need for public sector contracts, grants, and certain professional licences.
Budget 2026 VAT rate change: From 1 July 2026, the VAT rate for restaurant and catering services and hairdressing drops from 13.5% to 9%. If your business operates in hospitality or personal services, update your VAT3 returns and accounting software to reflect this from the July–August period onwards.
PAYE and Payroll Deadlines 2026 — Every Month, on the 23rd
If you employ staff in Ireland, payroll compliance under PAYE Modernisation is ongoing — not annual.
Real-time reporting: Every payroll submission must be received by Revenue on or before your employees’ pay date. There is no grace period.
Monthly PAYE, PRSI (Pay Related Social Insurance), and USC (Universal Social Charge) payments are due by the 23rd of the following month for ROS filers.
| Payroll Month | Payment Deadline |
| Jan-26 | 23-Feb-26 |
| Feb-26 | 23-Mar-26 |
| Mar-26 | 23-Apr-26 |
| …and so on | 23rd of the following month |
Enhanced Reporting Requirements (ERR): Non-taxable benefits — including travel and subsistence payments and the Small Benefit Exemption — must be reported to Revenue on or before the date they are paid to employees. This is a separate obligation from standard payroll.
Annual reconciliation for the 2026 payroll year is due in mid-February 2027.
Budget 2026 PRSI rate increase — effective 1 October 2026:
- Employee Class A PRSI rises to 4.35%
- Employer standard rate rises to 11.40% (on earnings above €552 per week)
Update your payroll software before your October 2026 payroll run. Getting this wrong means underpaying revenue, and interest runs from the original due date.
Capital Gains Tax (CGT) — 15 December 2026 & 31 January 2027
CGT applies to anyone who disposed of an asset in 2026 – property, shares, business interests, or other chargeable assets. The current CGT rate is 33%.
The critical point most people miss: the CGT payment deadline and the CGT return deadline are not the same date.
| Disposal Period | CGT Payment Due |
| 1 January – 30 November 2026 | 15-Dec-26 |
| 1 December – 31 December 2026 | 31-Jan-27 |
The actual CGT return (via Form 11 or Form CG1) is not due until 31 October 2027 — but interest on unpaid CGT runs from the original payment deadline, even if you file your return on time. Pay first, file later.
For companies disposing of development land, CGT payment follows the December/January schedule above — not the corporation tax schedule.
Capital Acquisitions Tax (CAT) — Gifts and Inheritances
CAT applies if you received a gift or inheritance in 2025 or 2026. The pay-and-file deadline depends on the valuation date of the gift or inheritance.
| Valuation Date | Pay & File Deadline | ROS Extension |
| 1 January – 31 August 2026 | 31-Oct-26 | 18-Nov-26 |
| 1 September – 31 December 2026 | 31-Oct-27 | N/A |
An IT38 return is required even if no tax is owed if the value of the gift or inheritance exceeds 80% of your tax-free group threshold. As with Form 11, both filing and payment must be completed through ROS to qualify for the November extension.
CRO Annual Return — Don’t Let This One Slip
Every Irish limited company must file a Form B1 annual return with the Companies Registration Office (CRO) within , days of its Annual Return Date (ARD).
Over 52,000 Irish companies have an ARD of 30 September — which puts the CRO filing deadline at 25 November 2026 for those companies.
Penalties for late CRO filing:
- €100 fixed penalty plus €3 per day, capped at €1,200
- Loss of audit exemption for the current financial year and the following financial year
That second penalty is the one that catches directors off guard. Losing audit exemption means your company must have its accounts independently audited — a cost that runs well into thousands of euro for most small Irish companies, for two years running. Following the tightening of audit exemption eligibility criteria post-July 2025, companies near the size thresholds should confirm their eligibility before assuming audit exemption applies.
File via the CRO’s CORE system online, and treat the CRO deadline as seriously as any revenue deadline.
What Happens If You Miss an Irish Tax Deadline?
| Tax Head | Surcharge / Penalty | Daily Interest Rate |
| IncomeTax (Form 11) | 5% (capped €12,695) within 2 months; 10% (capped €63,485) after 2 months | 0.0219% per day (~8% p.a.) |
| Corporation Tax (CT1) | Same surcharges; loss relief restricted by 25–50% | 0.0219% per day (~8% p.a.) |
| VAT (VAT3) | €4,000 fixed penalty per late return | 0.0274% per day (~10% p.a.) |
| PAYE / Payroll | Interest on underpayment; elevated Revenue audit risk | 0.0274% per day (~10% p.a.) |
| CRO Annual Return | €100 + €3/day (max €1,200) + 2-year loss of audit exemption | N/A |
| CGT | Interest from the original payment due date | 0.0219% per day (~8% p.a.) |
Outstanding returns also block your Revenue Tax Clearance Certificate, which is required for public sector tenders, grants, and certain professional licences. A missed VAT return in July can cost you a contract in September.
2026 Irish Tax Calendar — Month by Month
| Month | Key Deadlines |
| January | 23 Jan: VAT3 return (Nov–Dec 2025 period). 31 Jan: CGT payment for December 2025 disposals |
| February | 23 Feb: PAYE/PRSI/USC payment (January payroll); Annual payroll reconciliation for 2025 (mid-February) |
| March | 23 Mar: VAT3 return (Jan–Feb period); 23 Mar: PAYE/PRSI/USC (February payroll) |
| April | 23 Apr: PAYE/PRSI/USC (March payroll) |
| May | 23 May: VAT3 return (Mar–Apr period); 23 May: PAYE/PRSI/USC (April payroll) |
| June | 23 Jun: PAYE/PRSI/USC (May payroll); 23 Jun: First CT preliminary instalment (large companies, Dec 2026 year-end) |
| July | 23 Jul: VAT3 return (May–Jun period); 23 Jul: PAYE/PRSI/USC (June payroll); 1 Jul: VAT rate drops to 9% for hospitality and hairdressing |
| August | 23 Aug: PAYE/PRSI/USC (July payroll) |
| September | 23 Sep: VAT3 return (Jul–Aug period); 23 Sep: CT1 filing deadline (Dec 2025 year-end); 23 Sep: PAYE/PRSI/USC (August payroll) |
| October | 1 Oct: PRSI rate increase takes effect; 23 Oct: PAYE/PRSI/USC (September payroll); 31 Oct: Form 11 paper deadline; 31 Oct: CAT pay and file (Jan–Aug valuation dates) |
| November | 18 Nov: Form 11 ROS extended deadline; 23 Nov: VAT3 return (Sep–Oct period); 23 Nov: CT preliminary tax – small companies (Dec 2026 year-end); 23 Nov: PAYE/PRSI/USC (October payroll); 25 Nov: CRO annual return (30 Sep ARD companies) |
| December | 15 Dec: CGT payment (Jan–Nov 2026 disposals); 23 Dec: PAYE/PRSI/USC (November payroll) |
How to Avoid Missing Irish Tax Deadlines in 2026
1. Register on ROS early.
Getting your ROS Access Number (RAN) can take up to five working days. If you’re not already registered, do it now — not the week before a deadline.
2. Set internal cut-off dates.
For Form 11, have all your records with your accountant by mid-October. The ROS extension runs to 18 November, but it is not a buffer for slow record-keeping.
3. Never treat the ROS extension as a fall safety net.
If your bank payment fails outside ROS or you apply a different payment method, you lose the extension entirely, and the 31 October deadline applies.
4. Build a compliance calendar with recurring reminders.
PAYE is due on the 23rd every single month. VAT on the 23rd every two months. Put these in your calendar once and let the reminders run.
5. Consider outsourcing your bookkeeping and compliance.
If you are running a business and simultaneously chasing revenue deadlines, something will eventually slip. An outsourced bookkeeping partner manages the recurring monthly submissions – PAYE, VAT, and ROS – so the only deadlines you handle personally are the annual ones.
Stay Ahead of Every Deadline — Without Doing It Alone
2026 Irish tax deadlines are spread throughout the year, not just in October. The autumn cluster — Form 11, CT1 for December year-ends, CRO annual returns, and CAT — is the most pressurised period for Irish SMEs, but missing a VAT return in March or a PAYE payment in June carries its own cost.
Aone Outsourcing handles bookkeeping, VAT, payroll, corporation tax returns, and self-assessment for Irish SMEs year-round. You focus on running your business; we make sure revenue and the CRO never have a reason to send you a penalty notice. Talk to us about outsourced bookkeeping services in Ireland today.
Frequently Asked Questions
When is the income tax deadline in Ireland for 2026?
The standard deadline is 31 October 2026 for paper filers. If you both file and pay through ROS, the extended deadline is 18 November 2026, confirmed by Revenue in eBrief No. 034/26. This covers your 2025 tax year Form 11 return.
What is the CT1 filing deadline for companies with a December 2025 year-end?
23 September 2026. Corporation tax returns are due by the 23rd day of the ninth month after the end of your accounting period. Companies with different year-ends will have different CT1 deadlines across the calendar year.
When are VAT returns due in Ireland in 2026?
Most VAT-registered businesses file bi-monthly VAT3 returns. Each return and payment is due by the 23rd of the month after the period ends — for example, the January–February period is due 23 March 2026.
What is the ROS extended deadline for income tax in 2026?
18 November 2026, as confirmed by Revenue in eBrief No. 034/26. Both your return and your payment must be completed through ROS. If either is done outside ROS, the 31 October deadline applies — no exceptions.
What happens if I miss the Form 11 deadline?
A surcharge of 5% of your tax liability (capped at €12,695) applies if you file within two months of the deadline. Beyond two months, the surcharge rises to 10%, capped at €63,485. Interest at 0.0219% per day also runs on any unpaid tax from the original due date. These surcharges are set out in Section 1077E of the Taxes Consolidation Act 1997.
When is the GT due in Ireland for 2026?
If you disposed of an asset between 1 January and 30 November 2026, CGT payment is due by 15 December 2026. For disposals made in December 2026, payment is due by 31 January 2027. The CGT return itself is not due until 31 October 2027 — but interest runs from the payment deadline regardless.
What is the self-assessment deadline for submissions in Ireland for 2026?
Sforessm submissions cover the same Form 11 deadlines: 31 October 2026 on paper or 18 November 2026 through ROS. Sole traders, freelancers, and anyone with non-PAYE income are all within the self-assessment system.
