Missing a Revenue deadline is an entirely avoidable cost. A late income tax return attracts a surcharge. A late VAT return attracts interest. A late annual return to the CRO costs €1,200 per return and triggers a three-year mandatory audit requirement. None of these costs are large in isolation — but they add up, and they are all completely unnecessary.
The purpose of this guide is simple: put these dates somewhere visible, set a reminder two weeks before each one, and don’t pay Revenue anything you don’t have to.
I’ll update this guide annually. For now, here are the key dates for 2026.
Income Tax — Sole Traders, Partners, and Proprietary Directors
Preliminary Tax — 31 October 2026
If you are a sole trader or a proprietary director (a director who owns more than 15% of the company’s shares), you are required to pay preliminary income tax for the current year by 31 October. Preliminary tax must be at least 90% of your final liability for the year, or 100% of your prior year liability, whichever is lower.
Payment must also be accompanied by the filing of your Form 11 (income tax return) for 2025. If you use Revenue’s Online Service (ROS), you have an extended deadline for both payment and filing — typically to mid-November. Check revenue.ie for the exact extended deadline each year.
Failure to pay sufficient preliminary tax by the deadline results in an interest charge on the shortfall.
Pay and File — November 2026 (exact date TBC on ROS)
The full income tax return (Form 11) for the 2025 tax year, along with any balance of tax due, is due by 31 October 2026 (extended for ROS users). This is both a filing and a payment deadline.
Tip: Do not wait until October. If you engage an accountant, getting your records together by July or August gives time for proper planning — not just compliance. That advance preparation is also the best time to review your position against the measures introduced in Budget 2026.
Corporation Tax
Preliminary Corporation Tax
For companies with a tax liability of less than €200,000, preliminary corporation tax must be paid one month before the end of the accounting period. For a company with a 31 December year end, this falls on 30 November of the current year — meaning the 2026 preliminary tax for a 31 December company is due by 30 November 2026.
For companies with a tax liability of €200,000 or more, two instalments of preliminary tax apply — the first at six months into the accounting period, and the second one month before year end.
Corporation Tax Return — 9 months after year end
The CT1 (corporation tax return) and any balance of tax due must be filed and paid within nine months of the end of the accounting period. For a 31 December 2025 year end company, this means the return is due by 23 September 2026 (slightly less than nine months, because of the way Revenue calculates the due date).
For companies with a 31 March 2025 year end, the return is due by 23 December 2025. For 30 June 2025 year end, due by 23 March 2026.
Check your company’s specific year end and count forward nine months to find your CT1 deadline.
VAT
VAT returns and payments in Ireland operate on a two-monthly cycle for most businesses, though some smaller businesses are on a four-monthly or six-monthly schedule.
Bi-Monthly VAT Returns (most businesses)
| Return Period | Filing and Payment Deadline |
|---|---|
| November–December 2025 | 23 January 2026 |
| January–February 2026 | 23 March 2026 |
| March–April 2026 | 23 May 2026 |
| May–June 2026 | 23 July 2026 |
| July–August 2026 | 23 September 2026 |
| September–October 2026 | 23 November 2026 |
The 23rd of the month following the period end is the standard deadline. If you file and pay via ROS (which you should), this deadline applies. Paper filers have an earlier deadline of the 19th. If you are new to VAT or want to make sure you are handling it correctly, our plain-English guide to VAT in Ireland covers rates, registration, and the most common mistakes.
Annual VAT Return (small businesses)
If Revenue has agreed that you can file annually (this applies to businesses with a relatively small VAT liability), your annual VAT return is due by 23 January for the previous calendar year. The annual return must include a payment of any VAT balance due.
VAT Registration Threshold — 2026
The current VAT registration thresholds in Ireland are:
€80,000 per year for businesses supplying goods. €40,000 per year for businesses supplying services.
Once your turnover crosses these thresholds, you must register for VAT. Registration is required before, not after, you exceed the threshold — so if you can see you are going to breach it, register proactively.
PAYE / Employer Obligations
Monthly P30 (employer return)
If you have employees, you are operating PAYE on their salaries. Under PAYE Modernisation (which has been live since January 2019), payroll data must be submitted to Revenue on or before each pay date. This is the real-time element.
The monthly employer return (now the Payroll Submission Request in modern systems) and payment of PAYE/PRSI deducted is due by the 23rd of the month following the payroll period. So January 2026 payroll deductions are due by 23 February 2026.
P35 — Now Replaced
The annual P35 employer return has been replaced under PAYE Modernisation by the real-time system. There is no year-end P35 filing. Your payroll software should be submitting data to Revenue on or before each pay date throughout the year.
If you are operating payroll manually or on an outdated system and you are not submitting real-time data to Revenue, you are non-compliant and should address this immediately.
CRO — Company Annual Return
Every Irish limited company must file an annual return (Form B1) with the Companies Registration Office each year. The annual return date (ARD) is specific to each company — it is generally 6 months after your financial year end for the first return after incorporation, and then 12 months after the previous return.
Do not confuse the ARD with the corporation tax deadline. They are separate deadlines with separate consequences for missing them.
Failing to file the CRO annual return on time results in a late filing fee (€100 per day, up to a maximum of €1,200) and the loss of audit exemption for three years. I’ve written a separate, detailed article on the CRO strike-off process which is worth reading alongside this one.
How to find your ARD: Log in to the CRO website at cro.ie and search for your company. The annual return date is shown on the company record.
RCT — Relevant Contracts Tax (Construction Sector)
For principal contractors in the construction sector, RCT returns are filed monthly or quarterly, depending on the level of activity:
Monthly filers: return and payment due by the 23rd of the following month. Quarterly filers: return and payment due by the 23rd of the month following the quarter end.
Payment notifications for individual subcontractor payments must be made before each payment — this is an ongoing, per-transaction obligation, not just a periodic return. The detail is covered fully in my separate guide to RCT.
A Final Note on Penalties
Revenue’s interest rate on underpaid tax is 8% per annum (approximately 0.0219% per day). On top of interest, surcharges apply to late-filed income tax returns (5% surcharge up to 2 months late; 10% surcharge after 2 months, both subject to maximums). Penalties for non-compliance in areas like RCT and PAYE can be significant.
None of this is inevitable. The businesses I work with that have the cleanest Revenue relationships are simply the ones who plan ahead, keep their records current, and file on time. If you want to review your current compliance position or ensure you’re not missing any deadlines, my office is a phone call away. You can also browse our full library of taxation guides for more on each of these topics.
Paddy Malone FCA AITI
Paddy is the principal of Malone & Co. Chartered Accountants in Dundalk. A Fellow of Chartered Accountants Ireland and a Chartered Tax Consultant with the Irish Tax Institute, he has been advising businesses across County Louth and the North-East for over 35 years.