Preliminary tax is an advance payment of your income tax, USC, and PRSI for the current tax year. It is paid on 31 October (or mid-November via ROS) each year alongside your previous year's final tax return. It's effectively a deposit against your final tax liability.
Preliminary Tax Calculator Ireland 2026
Calculate how much preliminary tax you need to pay by 31 October 2026. Avoid interest charges by getting this right.
Preliminary tax — key rules
- Pay 90% of current year's estimated liability, OR
- Pay 100% of prior year's actual liability
- Deadline: 31 October (mid-November via ROS)
- Interest applies on underpayments at 0.0219%/day
- First year of self-employment: 90% of current year only
Calculate Preliminary Tax
Preliminary Tax Estimate
Estimated 2025 Liability
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Method 1: 90% of 2025 liability
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Method 2: 100% of 2024
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Preliminary Tax Due
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The calculator suggests the lower of Method 1 and Method 2 where both are available.
Estimate only. This is based on income tax only. The full preliminary tax includes USC and PRSI. Consult your tax adviser or ROS to confirm your exact liability before paying.
Frequently Asked Questions
You must pay at least one of the following: (1) 90% of your final liability for the current tax year; or (2) 100% of your final liability for the previous tax year. You choose whichever is lower, or pay 90% of your current year estimate if you can calculate it accurately.
If you pay less than 90% of your current year liability, or less than 100% of the prior year liability, Revenue charges interest on the underpayment from the payment deadline date until the balance is paid. The interest rate is 0.0219% per day. There is no fixed penalty, but interest can add up quickly on large underpayments.
Preliminary tax for the current year (2025) must be paid by 31 October 2025. If you file and pay online through ROS, the deadline is typically extended to around 14 November 2026. Revenue announces the exact extended deadline annually.
PAYE employees generally have tax deducted at source and are not required to pay preliminary tax unless they have additional non-PAYE income (e.g. rental income, freelance work). If your non-PAYE income is less than €5,000, you can declare it through a Form 12 rather than the full self-assessment system.
Preliminary tax is paid through the Revenue Online Service (ROS). You file a preliminary tax statement and pay the amount electronically. Payment can also be made by cheque to Collector General but this is less common. Bank transfers are not accepted directly.
Official Sources
This calculator is based on legislation and guidance from the following official sources:
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Revenue.ie — Preliminary tax
Revenue guide on calculating and paying preliminary tax.
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ROS — Revenue Online Service
File and pay your preliminary tax online through ROS.
Need an exact calculation?
IrishTaxTools provides estimates. D’Emilia Accounting can review your complete circumstances and provide professional assistance with Irish tax, payroll, VAT, bookkeeping and compliance.