Editorial and corrections policy

People use these pages to decide whether their tax code is right and how much tax to expect on a payslip. A wrong rate or rule can make them chase a refund that is not due, or miss one that is, so every figure points back to the text it was read on.

Who is responsible

Radif Partners, reachable at contact@taxcodecalc.co.uk.

What we read

• HMRC's Specification for PAYE Tax Table Routines, which payroll software follows, and the P9X notice of tax codes for each new year;
• the rates and thresholds for employers for each tax year, and HMRC's table of Income Tax rates and allowances;
• GOV.UK guidance on tax codes, emergency codes, K codes, Marriage Allowance, company benefits, the State Pension, overpayments and underpayments, and the HMRC online services;
• HM Treasury's Budget overview of tax legislation and rates, and the Scottish Government's announcements of the Scottish Budget.

Sources we refuse

Accountancy firms, refund companies, payroll vendors' marketing and forums never supply a figure here. A rule we cannot find in an HMRC or government text is not published as a rule. A rate that is not set yet is written as not published, with the date it is expected.

Review cycle

Rates and thresholds are re-read after each Budget, each Scottish and Welsh budget and before each 6 April; the tax code guidance at least every quarter. Announced changes are shown as coming, with their date, never as current.

Corrections

1. We open the source again.
2. We correct the parameter file and add an automated test for the case.
3. The site rebuilds and every page shows the new date.

Independence

No firm, payroll provider or government body pays for or reviews what is published here, and the site carries no affiliate link. See also the method page. Version of 29 October 2026.