How we check our figures

Every take-home figure on this site, on every calculator, guide and in the public API, comes from one tax engine. Each tax year is a separate set of rates (bands, credits, USC, PRSI and the rest) put through the same calculation, so a figure cannot drift from the rates underneath it. You can read every rate the engine uses for each year, with the official source for each, through the public API's rates endpoint.

The 2027 rates are provisional: taken from the official Budget publications on 6 October 2026, and re-checked against Revenue's own 2027 tables once Revenue publishes them.

On Budget day the Department of Finance publishes worked examples of what the new rates mean at set salaries. It computes them, not us, so they are the most direct check there is on our 2027 figures. Below is each published figure beside ours, rounded to the euro as the Department rounds. Every one matches.

The 2027 rates are provisional until Revenue publishes its own 2027 tables. When it does, every figure is re-checked against them.

We keep a second calculation written out longhand from Revenue's published 2026 figures, line by line, that never asks the engine for anything. If both were built on the same mistake they would agree, so the second one is deliberately separate. Here is the take-home pay each gives, to the cent, for a single person and a married couple on one income, aged 35. They agree to within a cent; where a cent appears, it is rounding of the separate tax lines, each of which is rounded to the cent before being added up.

• Every calculator is run through the same comparison as the table above on every change to the site, for every filing status and both live tax years.
• The payslip checker is tested against real Irish payslips transcribed by hand, never against payslips generated by our own engine, which would only prove it agrees with itself.
• Every official page we cite is checked weekly, and a dead source is flagged rather than left in place.
• Revenue's own tables are checked daily for the provisional year, so the re-check happens as soon as they are published.

Where Revenue, Citizens Information and the Department of Finance describe a rule differently, Revenue's wording governs. Where Revenue says nothing, we go to the next official source rather than keep what the code already does. The about page lists the sources.

A calculator works from what you tell it. Your own tax credits and cut-off are on your Tax Credit Certificate and your payslip; if they differ from the standard ones for your status, enter them under "Use my own tax credits and cut-off" for an exact answer. Figures are estimates for information, not tax advice, and Revenue's records are the final word. If a figure here disagrees with your payslip or your Revenue record, please tell us at contact@irishpaye.ie.