UK tax codes explained

Step 01

What a tax code is

Your tax code is used by your employer or pension provider to work out how much Income Tax to take from your pay or pension. HMRC tells them which code to use. You get a tax code for each employment or pension you have. Find your tax code online (check your tax code for the current year — sign in or create an HMRC account), in the HMRC app, on your payslip, or on a Tax Code Notice letter from HMRC if you get one. Online and in the app you can also see previous years and sign up for paperless notifications when your code changes. • Hub: gov.uk/tax-codes • Check Income Tax: gov.uk/check-income-tax-current-year

This page explains codes — it is not a third-party “tax code checker.” Use HMRC’s official services for your live code.

Step 02

1257L (and the standard pattern)

1257L is the tax code GOV.UK currently cites for most people who have one job or pension. How the numbers usually work: HMRC starts from your tax-free Personal Allowance, subtracts untaxed income and other deductions in the code (for example company benefits), then replaces the final digit with a letter. Example from GOV.UK: standard Personal Allowance £12,570 minus £1,570 medical insurance benefit leaves £11,000 tax-free → code 1100L. Letter L means you are entitled to the standard tax-free Personal Allowance. For 2026 to 2027 the Personal Allowance remains £12,570, which lines up with 1257L for a full standard allowance on one job. If your code has a K, the calculation is different — use HMRC’s guidance rather than the simple Personal Allowance example.

Step 03

BR, 0T, emergency and other letters

Letters describe your situation and how tax-free allowance or rate tables apply.

Under an emergency code, tax is worked out on that week or month only, as if you earned that amount every period — so you can temporarily over- or under-pay. New jobs without a P45 often use emergency coding until HMRC updates (GOV.UK: can take up to 35 days).

Step 04

Find it on your payslip

Most UK payslips show the tax code near the Income Tax deducted line (exact layout varies by payroll software). Also check your P60 or P45 and your HMRC Personal Tax Account — the online HMRC view is the source of truth for what HMRC holds. Illustrative fragment (anonymized — not a downloadable template): Employee: A. Example · Tax period: Month 6 · Tax code: 1257L · Gross pay: £3,200.00 · PAYE Income Tax / Employee NI on following lines. If the tax looks wrong, your code may be wrong. Follow GOV.UK guidance on incorrect tax codes rather than a third-party checker.

Step 05

How it affects take-home

A code that gives more tax-free pay usually withholds less Income Tax; a tighter or BR/0T-style code withholds more from that employment. Emergency codes can swing either way depending on that period’s pay. National Insurance is separate from the tax code (Class 1 uses its own thresholds). Student loan deductions follow their own plans. For an educational estimate of annual take-home after Income Tax and NI (not a substitute for HMRC coding), use the Counttaxes UK calculator for England & NI, Wales, or Scotland.

We do not change tax codes or contact HMRC for you. Educational estimates only — confirm with GOV.UK and your payslip.