What is a tax code and what does 1257L mean?
A 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. 1257L is the code currently used for most people with one job or pension, where L means the standard tax-free Personal Allowance.
Figures checked against gov.uk on . General information, not tax advice.
What the numbers and letter mean
gov.uk says a tax code is made up of numbers and letters. The numbers show how much tax-free income you get in the tax year: HMRC starts with your Personal Allowance, subtracts certain untaxed income and deductions, and replaces the final digit with a letter. For most people the result is 1257L.
Where to find yours
You can check your code in your HMRC online account, in the HMRC app, on your payslip, or on a Tax Code Notice if HMRC sent one. You get a separate code for each employment or pension you have, so someone with two jobs will have two codes.
If the tax taken looks wrong, gov.uk says your code may be incorrect and links to guidance on putting it right.
Tax codes and Self Assessment
If you also file Self Assessment, HMRC can sometimes collect a small bill by adjusting your code instead of asking for a lump sum. That route has conditions and a deadline of its own, covered in a separate entry.