Preliminary tax is your own estimate of the income tax, PRSI and USC you will owe for the current year, paid in advance by 31 October. If you are self-employed or have other income outside PAYE in Ireland, you pay it every year at the same time as you file the previous year’s tax return. This guide explains how much you must pay, the three safe harbour rules, and what happens in your first year.
Key facts
- What it is: an advance payment of income tax, PRSI and USC for the current tax year.
- Deadline: 31 October of the tax year, extended to 18 November if you pay and file through ROS.
- How much: at least the lowest of 90% of this year’s tax, 100% of last year’s tax, or 105% of the year before last (direct debit only).
- First year: usually nothing to pay, because last year’s self-assessed tax was normally nil.
- Underpaying: Revenue charges interest for each day late.
Who has to pay preliminary tax?
Anyone in Ireland’s self-assessment system pays preliminary tax. You must register for self-assessment if you are self-employed, or if your main income is rental, investment or foreign income, maintenance payments or fees exempt from PAYE. You must also register if your taxable non-PAYE income is more than €5,000, or your gross non-PAYE income is more than €30,000. If your non-PAYE income is below those amounts, you can usually declare it on a Form 12 through myAccount instead, and it is taxed through your PAYE tax credits.
How Pay and File works
By 31 October each year, you must do three things at once:
- Pay preliminary tax for the current year.
- File your tax return (Form 11) for the previous year.
- Pay any balance of tax still due for the previous year.
For example, by 31 October 2026 you must pay preliminary tax for 2026, file your 2025 return, and pay any balance for 2025. If you pay and file online through ROS, the deadline moves to 18 November.
How much preliminary tax do you need to pay?
To avoid interest, your preliminary tax must be at least the lowest of these three amounts:
| Option | Amount | Best for |
|---|---|---|
| Current year | 90% of the tax due for this year | When your income has dropped this year |
| Previous year | 100% of the tax due for last year | When your income is steady or rising |
| Pre-preceding year | 105% of the tax due for the year before last | Only if you pay by direct debit, and that year’s tax was not nil |
“Tax” here means income tax, PRSI and USC together.
A worked example
Say your total income tax, PRSI and USC was €10,000 for last year, and you expect this year’s bill to be about €8,000 because work was quieter.
- 90% of this year: €7,200
- 100% of last year: €10,000
The minimum is €7,200. The risk is that if this year turns out better than expected and your real bill is €9,000, then €7,200 is less than 90% of the actual tax (€8,100), and Revenue can charge interest. Paying 100% of last year’s tax is the safe option when you are unsure, because it is a fixed figure you already know.
Preliminary tax in your first year
In your first year of self-assessment you can choose either:
- 100% of the previous year’s liability. This is normally nil in your first year, so usually you pay no preliminary tax at all, or
- 90% of this year’s tax, which reduces the amount you will need to pay the following year.
Be careful with the first option. Paying nothing in year one means that the following October you pay the full balance for year one and preliminary tax for year two at the same time. Many new sole traders are caught out by this double bill, so set money aside from day one.
How to pay
- ROS: by ROS Debit Instruction from a bank account, or by debit or credit card.
- myAccount: by single debit instruction from a bank account, or by debit or credit card.
- Direct debit: set up through ROS. This is the only way to use the 105% option.
Only Visa and Mastercard cards are accepted.
Paying late or filing late
Late or insufficient preliminary tax attracts interest for each day, or part of a day, past the deadline. Filing your return late also brings a surcharge:
- filed less than two months late: 5% of the tax due, up to €12,695
- filed more than two months late: 10% of the tax due, up to €63,485.
A 10% surcharge can also apply if your Local Property Tax obligations are not met, even when you pay and file income tax on time.
Frequently asked questions
When is preliminary tax due in Ireland?
By 31 October of the tax year it relates to, or by the ROS extended date (18 November in 2026) if you pay and file online.
Does preliminary tax include PRSI and USC?
Yes. It covers your estimated income tax, PRSI and USC for the year.
Do I have to pay preliminary tax in my first year as a sole trader?
Usually not, because you can base it on 100% of last year’s liability, which is normally nil. But you will then pay your first full year’s tax and second year’s preliminary tax together the following October.
What if I overpay preliminary tax?
The overpayment is set against your final liability when you file that year’s return, and any excess can be refunded or offset.
Do companies pay preliminary tax?
Yes, companies pay preliminary corporation tax under separate rules and dates. This guide covers income tax for individuals.
Related guides
- Sole trader vs limited company in Ireland
- How to start a business in Ireland
- VAT registration threshold in Ireland
- How to register as an employer in Ireland
Sources
- Revenue: What is preliminary tax?
- Revenue: Pay and file system
- Revenue: Who should register for self-assessment?
Checked against Revenue guidance in October 2026. This guide is general information, not tax advice. For your own situation, speak to an accountant or contact Revenue. More business guides and news in our Finance section.
