Who is behind Tax Code Calc

Tax Code Calc is published by Radif Partners, a company that builds free tools on public rules and public data. This site is for employees and pensioners in the United Kingdom who look at the code on a payslip or an HMRC letter and want to know, in a minute, what it means, whether it is right and what it does to their pay.

What the site does

It decodes any PAYE tax code, works out the tax on a given payslip with HMRC's cumulative method, estimates the code a situation points to and the gap over the year, shows what comes back after an emergency code, compares two codes and explains K codes with their 50% limit. Every code and situation has its own page and calculator. Everything is free, needs no account, and what you type stays in your browser.

Where the rules come from

From primary sources only: HMRC's Specification for PAYE Tax Table Routines, the rates and thresholds for employers, the P9X notice, HMRC's guidance on GOV.UK, HM Treasury's Budget overview and the Scottish Government. Every page links to the texts behind it. The method page explains each calculation.

What we are not

We are not HMRC, GOV.UK, a payroll bureau, an accountant or a tax refund company. We cannot see your tax record, change your code or claim anything for you; only HMRC can, through your online account, the HMRC app or by phone. The results are estimates from published rules. The site uses no official logo or brand.

How the site is paid for

The site sells no service, takes no commission, collects no contact details and recommends no firm. If advertising is added one day, it will never sit inside a calculator, and it cannot use what you type, which never leaves your browser.

Tell us when something is wrong

Write to contact@taxcodecalc.co.uk with the page and the figure, ideally with a link to the GOV.UK page that says otherwise. The editorial policy explains how a correction is made and dated. The site has 46 pages of guides and calculators.

Rates and rules last checked on 29 October 2026.