1257L tax code: what the numbers and letters mean

1257L is the standard code for someone with one job or pension in 2026/27. It gives the full £12,570 Personal Allowance, and the other numbers and letters show when that changes.

Updated 9 October 2026. Facts checked against GOV.UK on 9 October 2026.

How the code is built

GOV.UK describes the number part as HMRC starting from your Personal Allowance, taking off items such as untaxed income or company benefits, and then replacing the final digit with a letter. The final 0 of £12,570 is replaced by the letter L, which gives 1257L.

The L means you are entitled to the standard tax-free Personal Allowance. GOV.UK says 1257L is the code used for most people who have one job or pension.

Why you get 1257L

For 2026/27 the standard Personal Allowance is £12,570. On the starter checklist, statement A gives the current personal allowance on a cumulative basis, which is 1257L. Statement A applies if this is your first job since 6 April and you have not received taxable Jobseeker’s Allowance, Employment and Support Allowance or Incapacity Benefit since then.

The income tax bands for 2026/27 in England, Wales and Northern Ireland are as follows. Basic rate 20% on £12,571 to £50,270. Higher rate 40% on £50,271 to £125,140. Additional rate 45% above £125,140. The Personal Allowance starts to fall once adjusted net income is above £100,000, and is zero at £125,140. Scotland has different bands.

What changes the number

The number moves when HMRC has different information about your income or allowances. These are the usual causes.

Benefits from your employer. GOV.UK gives an example: a £1,570 medical insurance benefit reduces the allowance to £11,000, which gives a code of 1100L.
Tax owed from earlier years, or other untaxed income such as a State Pension. This gives a K code. The amount owed is added to your taxable pay, and GOV.UK says an employer cannot take more than half of your pre-tax wages or pension under a K code.
Marriage Allowance. An M means you have received part of your partner’s allowance, and an N means you have passed part of yours to your partner. For 2026/27 the transfer is £1,260, which can reduce tax by up to £252.
Other calculations. A T in the code means the allowance has been worked out in another way.
Where you live. An S prefix means your income is taxed at the Scottish rates, and the bands in Scotland are different. A C prefix means the Welsh rates apply.

What to check on your payslip

Start with the code shown on the payslip. Then check these points.

If you have one job, the code should be 1257L unless one of the changes above applies.
If you have two jobs, only one should carry 1257L, unless HMRC has split it. The other should be BR, D0 or D1. GOV.UK says the Personal Allowance is usually given to the job that pays you most.
Check for an S or C prefix. Scottish and Welsh income tax rates depend on where you live, not where you work. If the prefix does not match your home, tell HMRC.
Check for a W1, M1 or X suffix. That means the code works on a non-cumulative basis, which is covered in the W1 and M1 guide.

W1 and M1 emergency tax codes: why each pay day is taxed on its own, and how the code ends
The BR tax code: all of a job’s pay taxed at 20%, usually on a second job

If the code is wrong

Start by checking the code in the HMRC app or your personal tax account. Both show the codes HMRC holds for each job. GOV.UK says wrong or missing details can cause a wrong code, and that you can update them in your personal tax account or the HMRC app.

If the code is still wrong after that, contact HMRC. Keep your payslips and any Tax Code Notice letter, because they show the code you were given and when it applied.

The preset below

The calculator preset is a single job at £12.71 an hour for 25 hours a week, on 1257L. £12.71 is the National Living Wage for workers aged 21 and over from 1 April 2026. Try changing the code to BR to see how much the allowance matters for the estimate.

Shift pattern take-home pay calculator: the full calculator, with nights, weekends, bank holidays and a second job

What the code does not cover

The tax code only covers Income Tax. National Insurance is worked out separately, using its own thresholds, and student loan repayments are set by your plan type rather than by the number in your code.

If something on your payslip does not match the code, check each deduction on its own line. A wrong student loan plan, for example, does not change the tax code.

Related guides

Sources

This is an estimate, not financial or tax advice. Your payslip is the final figure.