Tax Code Checker
Type in the tax code from your payslip and find out exactly what it means, how much tax-free income it gives you, and roughly how much tax it will take from your pay.
Start here
How to use this calculator
Copy the tax code exactly as it appears on your payslip or P60, and enter it above.
Enter your tax code
Codes like 1257L, S1257L, BR, K475 and 0T are all supported, with or without a W1/M1 suffix.
Read what it means
See a plain-English explanation of your code, and how much tax-free income it gives you (or adds to your taxable pay, for K codes).
Add your salary to estimate the tax
Enter your annual pay from that job or pension to see roughly how much Income Tax it will take — and how that compares with the standard code.
Why it matters
Why your tax code is worth checking
Your tax code tells your employer or pension provider how much of your income to pay tax-free before working out the rest. Most people are on the standard code for the year (1257L in England, Wales and Northern Ireland, or S1257L in Scotland), giving the full £12,570 Personal Allowance. But codes change for all sorts of reasons — a new job, more than one income, company benefits, unpaid tax from a previous year, or Marriage Allowance — and an out-of-date or wrong code can mean paying too much or too little tax without realising it.
If you have more than one job or pension, it’s normal — not a mistake — for HMRC to give your full Personal Allowance to your main income and use a BR, D0, D1 or 0T code (no tax-free allowance) on the others. This tool shows you what your code means either way, so you can judge whether it looks right for your situation.
The K code
Why some codes start with K
A K code means the opposite of most codes: instead of giving you a tax-free amount, it adds an amount to your taxable pay before tax is calculated. This happens when you have income or deductions larger than your Personal Allowance that aren’t being taxed anywhere else — common examples are a company car or other taxable benefit, State Pension, or repaying tax owed from an earlier year. By law, your employer or pension provider can never take more than half your pre-tax pay in any single pay period because of a K code, however large the number in the code is.
Questions
Common questions
What does the W1, M1 or X at the end of my code mean?
This marks your code as “non-cumulative” or emergency — each payday is worked out on its own, without looking at what you’ve earned or been taxed so far this tax year. It’s often temporary, for example when you start a new job and your new employer doesn’t have your full pay history yet, and is usually corrected by HMRC or automatically switched to a cumulative code later in the year.
Why does my tax code have a letter at the start?
An S at the start means you’re taxed under Scottish rates and bands; a C means you’re taxed under Welsh rates. Wales currently sets its rates at exactly the same level as England and Northern Ireland, so a C code produces the same tax as no prefix at all for 2026/27 — but Scotland’s six bands are different, which is why the same numeric code can mean a different amount of tax depending on the letter in front of it.
Is BR always wrong?
No — BR (or SBR/CBR in Scotland/Wales) is very often correct if this is your second job or pension. HMRC normally puts your full Personal Allowance against your main income and taxes the rest of your income at the basic rate with no allowance, which is exactly what a BR code does. It’s only worth querying if you don’t actually have another income using up your allowance elsewhere.
What should I do if I think my tax code is wrong?
Check your Personal Tax Account on gov.uk, which shows the code HMRC currently holds for you and why, or contact HMRC directly. This tool explains what a code means and gives an estimate of the tax it produces — it can’t change your code or tell HMRC anything on your behalf.
Does this include National Insurance?
No — a tax code only ever affects Income Tax. The estimate here shows Income Tax alone on the income you enter; use our Take-Home Pay Calculator for a full picture including National Insurance and student loan deductions.
Where these figures come from. Tax code letter meanings, the K-code mechanism and its 50%-of-pay cap, and the special BR/D0/D1/0T/NT codes are taken from gov.uk and HMRC’s PAYE Manual. Income tax bands are taken from gov.uk for the 2026/27 tax year. Welsh rate parity with England/NI is confirmed via HMRC’s Welsh Rates of Income Tax annual report. All figures were checked on 23 September 2026. The Scottish SD2 (advanced rate) and SD3 (top rate) codes are shown based on Scotland’s published band structure, as HMRC’s own code list does not state every one of these individually.
What your tax code means (gov.uk) · K codes explained (gov.uk) · Understanding tax code numbers (gov.uk)
How we calculate · Editorial policy. This is general information, not tax advice.