Irish Preliminary Tax Calculator
Self-employed people in Ireland must pay preliminary tax by 31 October each year. Enter your estimated current-year tax, prior-year tax, and (optionally) pre-prior-year tax — we'll show the minimum you must pay to avoid interest charges.
How is this calculated?
Preliminary tax is the LOWER of: 90% of estimated current-year liability, 100% of prior-year liability, or 105% of pre-prior-year liability (the 105% option is only available if pre-prior > 0 and you pay by direct debit). The figure includes income tax, USC, and PRSI.
Frequently Asked Questions
What is preliminary tax in Ireland?
An advance payment toward your current-year tax liability. Self-assessed taxpayers must pay it by 31 October each year. Underpayment can attract interest at 0.0219% per day (~8% per year) plus potentially a 5% surcharge on the balancing return.
Why are there three options?
The three options give flexibility for different income patterns. Steady-income filers usually pick 100% of prior year (predictable, no estimation risk). Falling-income filers benefit from 90% of current. Direct-debit payers get the 105% pre-prior option for smoother monthly payments.
When is preliminary tax due?
By 31 October each year (the same date as the prior-year balancing payment and Form 11 return). Filing electronically via ROS extends the deadline to mid-November (typically). Direct debit payers spread the amount over monthly direct debits during the year.
Do PAYE workers pay preliminary tax?
Generally no — PAYE is collected at source by your employer and treated as full payment. Preliminary tax applies to income that doesn't have tax deducted at source: self-employment, rental, foreign income, and substantial investment income.
What if I pay too much preliminary tax?
Overpayments are credited against your final liability when you file the balancing return. If still in credit after that, you can claim a refund or carry forward. There's no penalty for overpaying — just an opportunity cost on the cash held.
Last updated: May 2026 · Rates sourced from Revenue