Tax code checker UK (2026/27)

The code and the annual estimate

Code numbers usually indicate an annual tax-free amount when multiplied by ten. BR and D codes allocate no allowance and apply a flat rate to that employment. A 0T code gives no allowance but still applies normal bands.

K codes add an amount to taxable pay. Actual payroll restricts tax collection in a pay period; the displayed annual comparison is not a reconstruction of that payroll record.

Scottish and emergency markers

An S prefix identifies Scottish employment Income Tax treatment; a C prefix identifies Welsh treatment. Scottish flat-code rates differ from similarly named rest-of-UK codes.

W1, M1 and X indicate non-cumulative treatment. They are decoded here, but annual figures cannot reproduce a specific period’s deduction without pay frequency, year-to-date earnings and previous tax.

Check a code with HMRC

Compare your employment, benefits and estimated income in your HMRC account. Ask payroll which code and basis were applied.

Correcting information may lead to a revised code or a separate tax calculation. This tool does not promise that a code will change immediately or that a refund will appear on the next payslip.

Sources and next steps

• HMRC tax codes
• Updating a tax code
• Tax-code guide
• Emergency-tax comparison

Reviewed 22 October 2026 by the AfterTaxUK Editorial Team. Check the applicable year and circumstances before relying on an estimate.