About the UK Tax Code Checker
This tax code checker explains what your UK PAYE tax code means and how much tax-free pay it gives you in the 2026/27 tax year. Type the code exactly as it appears on your payslip, P45, P60 or in the HMRC app — for example 1257L, 1383M, K475, BR, D0, 0T, S1257L or 1257L M1 — and it decodes the number, the letter, any S (Scotland) or C (Wales) prefix and any emergency marker such as W1, M1, X or NONCUM.
Enter your yearly pay from that job and the checker also estimates the income tax your employer should deduct over a full year using that code, so you can spot an obviously wrong code. The standard code for 2026/27 is 1257L, worth £12,570 of tax-free pay; a different number usually means HMRC is adjusting your allowance for benefits, unpaid tax, a second job or the £100,000 taper.
The estimate assumes the code applies for the whole year, uses the 2026/27 rates (20/40/45% in England, Wales and Northern Ireland, or Scotland’s 19%–48% bands) and treats the tax-free amount as the code number × 10. Payroll software works period by period and adds up to £9 to the free pay, so real deductions can differ by a few pounds. It does not include National Insurance.
With the default inputs, the tax-free pay from this code (per year) is £12,570.00. Change any value above to recalculate instantly.
How to use the uk tax code checker
- 1Find your tax code on your payslip, P45, P60 or in the HMRC app.
- 2Type it into the box exactly as shown, including any S, C, K or W1/M1 parts.
- 3Enter your yearly pay from the job the code applies to.
- 4Read what the code means, your tax-free pay and the estimated tax for the year.
- 5If the code looks wrong, check your coding notice and contact HMRC.
Formula and method
The number in a tax code is your yearly tax-free pay divided by 10, so 1257L means £12,570 and 1383M means £13,830 (the standard allowance plus £1,260 of Marriage Allowance received). HMRC starts from your Personal Allowance and subtracts things like taxable benefits, untaxed income or underpaid tax from earlier years, then adds anything that increases your allowance. A K code means the deductions exceed your allowance, so the amount is added to your taxable pay instead; the overriding limit stops more than 50% of pay being taken.
Codes without a number apply one rate to everything: BR is 20%, D0 is 40% (21% in Scotland), D1 is 45% (42% in Scotland), and the Scottish SD2 and SD3 codes use 45% and 48%. 0T gives no allowance but normal bands, and NT means no tax. The estimate applies the 2026/27 bands to pay above the tax-free amount for a full year.
- L, M, N, T
- Letters showing how your allowance was worked out
- S / C
- Prefix for Scottish or Welsh income tax rates
- W1, M1, X
- Emergency (non-cumulative) marker
Worked examples
Standard 1257L on £35,000
1257L gives £12,570 of tax-free pay. The remaining £22,430 is taxed at 20%, so about £4,486 a year — £373.83 a month — should be deducted.
K475 on £40,000
K475 adds £4,750 to your taxable pay, so tax is worked out on £44,750: £37,700 at 20% (£7,540) plus £7,050 at 40% (£2,820), a total of £10,360 — well under the 50% overriding limit.
Scottish emergency code S1257L W1 on £50,000
The S prefix means Scottish rates and W1 means each week is taxed on its own. Over a full year the £37,430 above the allowance is taxed £753.73 + £2,597.80 + £2,968.56 in the 19–21% bands and £2,661.96 at 42%, about £8,982.05.
Second job on BR
BR gives no tax-free pay on this job because your allowance is used elsewhere, so every pound is taxed at 20%: £2,400 on £12,000.
Frequently asked questions
What does tax code 1257L mean?+
1257L is the standard tax code for 2026/27. It means you get the full £12,570 Personal Allowance from this job, and the L shows it is the standard allowance with no adjustments for benefits, Marriage Allowance or the £100,000 taper.
What is an emergency tax code?+
An emergency code — 1257L W1, 1257L M1 or 1257L X — is used when your employer does not have full details, often in a new job. Each pay period is taxed on its own instead of cumulatively, so you may overpay until HMRC sends a correct code.
What does a K tax code mean?+
A K code means you have income that is not taxed elsewhere (such as a company car, state pension or unpaid tax) worth more than your allowances. The number × 10 is added to your taxable pay, but no more than 50% of any payment can be taken in tax.
Why is my tax code different from 1257L?+
Common reasons are taxable benefits like a company car or medical insurance, collecting underpaid tax from an earlier year, Marriage Allowance (M or N), a second job, or income over £100,000 reducing your allowance. Your HMRC coding notice lists each adjustment.
What do BR, D0 and 0T mean?+
BR taxes all income from the job at 20%, D0 at 40% (21% in Scotland) and D1 at 45% (42% in Scotland), usually for second jobs or pensions. 0T gives no tax-free allowance but still uses the normal tax bands.
Why does payroll give me slightly more than code × 10 tax-free?+
HMRC’s PAYE tables add up to £9 to the free pay for each code (1257L gives about £12,579 a year), and tax is worked out each pay period. That is why payslips can differ by a few pounds from a simple annual estimate.
Tax results are estimates based on published rules and simplified assumptions. They are not tax advice — check official guidance or a tax professional for your situation.