The Form 11 deadline in 2026 is Saturday 31 October 2026. By that date you must file your 2025 income tax return, pay any balance of 2025 income tax, and pay preliminary tax for 2026. If you both pay and file through ROS, Revenue has extended the deadline to Wednesday 18 November 2026.
If you are a sole trader, you are in the self-assessment system and file a Form 11 every year. Revenue also requires self-assessment registration where your taxable non-PAYE income exceeds €5,000, or your gross non-PAYE income exceeds €30,000.
Other triggers include having rental, investment or foreign income as your main source of income, and profits from share options or share incentives. If you registered for self-assessment since 2015, Citizens Information notes that you are required to file and pay online.
Not sure whether you are a sole trader or should be trading through a company? Our guide on sole trader vs limited company in Ireland covers the trade-offs.
Revenue's pay and file system bundles three jobs into one date. By 31 October 2026 you must:
Income tax here includes PRSI and USC. Revenue defines preliminary tax as your estimate of the income tax, PRSI and USC you expect to pay for the year.
| Date | What is due | Who it applies to |
|---|---|---|
| Saturday 31 October 2026 | 2025 Form 11 filed, 2025 balance paid, 2026 preliminary tax paid | Everyone in self-assessment who does not both pay and file on ROS |
| Wednesday 18 November 2026 | The same three items | Only those who both file and pay through ROS |
| 9th of each month | Monthly preliminary tax direct debit taken from your bank | Direct debit payers (next working day if the 9th is a weekend or bank holiday) |
| Within two months of the deadline | Late return: 5% surcharge, capped at €12,695 | Anyone who misses the filing date |
| More than two months after the deadline | Late return: 10% surcharge, capped at €63,485 | Anyone who misses the filing date |
Revenue confirmed in eBrief No. 034/26 that customers who file their 2025 Form 11 and make the payment for the 2025 balance and 2026 preliminary tax through ROS have until Wednesday 18 November 2026.
The condition is strict. You must both pay and file through ROS. If only one of the two is done through ROS, the extension does not apply and both the return and the payment are due by 31 October 2026.
Treat 31 October as the real deadline and the extra 18 days as a buffer, not a plan.
To avoid interest, your preliminary tax must be at least the lowest of these three amounts:
This suits a business whose profits are falling, because 90% of a smaller 2026 bill can be less than last year's bill. The risk is that you are estimating. If 2026 turns out better than expected, your payment can fall below 90%, and unless it still meets one of the other two tests, interest applies.
This is often the simplest choice because it is based on a known figure: your 2025 liability, which you are calculating anyway when you file the 2025 return.
The 105% option only applies where you pay preliminary tax by direct debit. It does not apply if your tax for the pre-preceding year (2024 for the 2026 tax year) was nil.
Revenue's direct debit guidelines say payments come out on the 9th of each month, the monthly amount cannot be less than €10, and you can change the amount as often as you need. Under section 959AP TCA, you are treated as paying on time if every scheduled direct debit is made, and the Finance Act 2025 removed the minimum number of instalments. Revenue's guidance does not say how late in a year a new direct debit can start and still count for the 105% option, so if you are not on direct debit yet, check with your accountant before relying on it for 2026.
Revenue's interest guidelines are clear: if insufficient preliminary tax is paid, or it is paid late, the due date for the full amount of the tax reverts to the date the preliminary tax should have been paid. In practice, interest can then run on the whole year's balance, not only the shortfall.
If 2026 is your first year in self-assessment, a preliminary tax payment may not be required. Revenue says you can pay 100% of the previous year's liability, which for a new trader is generally nil, or 90% of your tax for the current year.
Paying something now can still make sense. Revenue points out that paying 90% in your first year reduces the payment due the following year, which is when many new traders get a shock: the first full balance and the next year's preliminary tax land on the same day.
New businesses also get some relief on surcharges. Revenue's surcharge manual says that for a new business, the surcharge only applies to delays from the business's second filing date. This does not apply where the owner already has an existing business, or where a jointly assessed spouse or civil partner has one.
Take a sole trader with these income tax figures (including PRSI and USC):
Step 1: the 2025 balance
€18,500 liability minus €16,000 preliminary tax already paid = €2,500 balance due for 2025.
Step 2: the 2026 preliminary tax options
| Option | Calculation | 2026 preliminary tax | Paid how | Balance left for 31 October 2027 |
|---|---|---|---|---|
| 90% of 2026 | €22,000 x 90% | €19,800 | Lump sum by 31 October (or 18 November on ROS) | €22,000 minus €19,800 = €2,200 |
| 100% of 2025 | €18,500 x 100% | €18,500 | Lump sum by 31 October (or 18 November on ROS) | €22,000 minus €18,500 = €3,500 |
| 105% of 2024 | €16,000 x 105% | €16,800 | Monthly direct debit during 2026 | €22,000 minus €16,800 = €5,200 |
Step 3: what leaves the bank account at pay and file
The 100% option is the lowest lump sum here, because profits are rising. The 105% option spreads the cost across the year but leaves the largest balance for October 2027.
Step 4: the cost of getting it wrong
If the €2,500 balance is paid 30 days late, interest is €2,500 x 0.0219% x 30 = €16.43.
If the 2025 return is filed late but within two months of the deadline, the surcharge is 5% of the €18,500 liability = €925. Filed more than two months late, it is 10% = €1,850.
The surcharge is worked out on the year's full liability (after any PAYE credit, before credit for tax paid directly), so it applies even if the tax itself was paid in full and on time.
Revenue applies a surcharge under section 1084 of the Taxes Consolidation Act 1997 when a return is filed late:
The surcharge is then treated as tax, so it can attract interest too. A return that is carelessly or deliberately incorrect can be treated as not filed on time unless the error is corrected before the deadline.
Revenue also says a 10% surcharge may apply to your final liability if your Local Property Tax obligations are not met.
Interest on late income tax is charged at 0.0219% per day, a rate that has applied since 1 July 2009. It is charged for each day or part of a day the payment is late.
Interest arises when too little preliminary tax is paid, when preliminary tax is paid late, or when the balance is paid late. If a Revenue review follows, our guide to a Revenue audit or compliance intervention explains what to expect.
We prepare and file Form 11 returns for sole traders and work out which preliminary tax option leaves you in the best cash position. You can book a quick chat, see our tax services, or keep every deadline in view with our free compliance calendar. For a fee estimate, try our online quote.
The standard deadline is 31 October 2026 for the 2025 return, the 2025 balance and 2026 preliminary tax. If you both pay and file through ROS, the deadline is extended to 18 November 2026.
No. Revenue says you must both pay and file through ROS to get the 18 November 2026 date. If only one is done through ROS, both are due by 31 October 2026.
At least the lowest of 90% of your 2026 tax, 100% of your 2025 tax, or 105% of your 2024 tax. The 105% option is only for direct debit payers and does not apply if your 2024 tax was nil.
A preliminary tax payment may not be required in your first year, because 100% of the previous year's liability is generally nil. You can choose to pay 90% of the current year's tax instead, which reduces the following year's payment.
5% of the tax liability, up to €12,695, if filed within two months of the deadline, and 10%, up to €63,485, after that. It applies even if the tax was paid on time.
0.0219% per day, for each day or part of a day the tax is late. If preliminary tax is too low or late, the due date for the full year's tax reverts to the preliminary tax due date.
Last checked: 3 October 2026. Written by the M.A. Whately team. This guide is general information, not advice for your situation; talk to us before acting on it.
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