The number
For an ordinary numeric code, the number multiplied by ten approximates the tax-free allowance allocated to that job or pension. A 1257 code therefore represents about £12,570.
2026/27 PAYE explainer
UK tax code calculator and decoder
Decode the letters and numbers on your payslip, then see an indicative annual take-home estimate using that code. Nothing you enter is sent to us.
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Decode the code on your payslip
Enter it exactly as shown, including S, C, K, W1 or M1.
Used only for the indicative annual estimate below.
Try an example
Common format recognized
1257L
Approximately £12,570 of tax-free allowance
1257L indicates an allowance of approximately £12,570 at this source and standard Personal Allowance rules.
- Region
- England or Northern Ireland
- Allowance
- £12,570
- Tax treatment
- Progressive tax bands
- Payroll basis
- No emergency marker detected
- Without W1, M1, X or NONCUM, a normal code is generally operated on a cumulative basis.
- The number is an approximation of the allowance encoded by HMRC, not a guarantee of your final annual tax bill.
Indicative take-home with this code£2,693/month
£5,486 estimated annual Income Tax.
Read your payslip
How UK tax codes are structured
A tax code tells an employer or pension provider how HMRC wants PAYE Income Tax operated for that source of income.
The letters
L commonly accompanies the standard allowance. M and N relate to Marriage Allowance, T signals other calculations, while S and C identify Scottish and Welsh treatment.
Special codes
BR, D0 and D1 apply one rate to all pay from a source. 0T gives no allowance but retains progressive bands. K codes add an amount to taxable pay.
Emergency markers
W1, M1, X and NONCUM generally operate the code on a non-cumulative basis. An exact calculation needs the pay period and payroll history, which this annual tool does not request.
Important boundary
How do I check if my tax code is correct?
This calculator explains common code formats and provides an annual illustration. It cannot confirm that a code is correct for your circumstances or change the information held by HMRC. Use the official services below to understand your code, check HMRC's income details and update anything that is wrong or missing.