Finance & Irish taxes · Calculator companion · By K Imports
Preliminary Income Tax payment: practical guide
This guide explains how to use the Count.ie preliminary income tax payment. Compare the 90%, 100% and qualifying 105% bases before payments already made. Follow the inputs, method and worked example below, then compare your own scenario.
Guide written .
Open the Preliminary Income Tax payment calculatorWhat to prepare
- Find the relevant statement, payslip or transaction record rather than estimating from a bank balance.
- Identify the tax year, transaction date and whether each amount is gross, net, annual or monthly.
- Separate known facts from assumed rates and check eligibility against the linked official sources.
Understand the inputs
The calculation method
Minimum valid basis is the lower of 90% current, 100% previous, or qualifying 105% pre-previous liability; subtract payments already made.
Worked example
Illustrative inputs and their result.
Example inputs
- Estimated current-year Income Tax, USC and PRSI (€)
- 15000
- Previous-year liability (€)
- 12000
- Pre-previous-year liability (€)
- 10000
- Qualifying direct-debit arrangement
- No
- Preliminary tax already paid (€)
- 0
Calculated example result
- Additional Preliminary Tax
- €12,000.00
- Minimum Preliminary Tax
- €12,000.00
How to interpret the result
Distinguish a tax saving, a tax bill, cash received and money remaining: they are not interchangeable. An estimate does not establish eligibility, filing compliance or when a refund will be paid.
Compare the same income or transaction under one changed assumption at a time. Keep a record of the year, date and assumptions so a change in the result can be explained.
Common mistakes to avoid
- Do not mix tax years or apply a newly announced measure to an earlier transaction.
- Avoid counting an allowance, credit, contribution or loss twice.
- Check exclusions and personal circumstances before relying on the headline result.
Assumptions and sources
Rates/conditions reviewed against the linked official sources on 5 October 2026. Confirm the stated scope before relying on the result.
Rules checked . This date comes from the tool’s review notes and applies only to its documented scope, not to every selectable scenario.
Sources and further information
If your case falls outside this scope, use a more suitable calculator or contact us about an unclear method.