What does the 1257L M1 tax code mean?
1257L M1 means: Tax-free allowance of about £12,570.00 a year. In short: the standard allowance on an emergency, non-cumulative basis. A UK tax code is the instruction HMRC sends your employer for the 2026/27 tax year (6 April 2026 to 5 April 2027): it sets how much of your pay is tax-free before income tax is deducted through PAYE, so the code on your payslip directly decides your take-home. The standard code for most employees with one job is 1257L, worth £12,570 of tax-free income a year, any other code should have a reason behind it (a company benefit, a second job, an HMRC adjustment), and a code that's wrong for your situation means paying the wrong tax every single payday until it's fixed. Decoded below against HMRC's rules as checked on 2026-08-28, with what 1257L M1costs or saves against the standard code.
Decoded
- L: you get the standard personal allowance.
- M1: emergency (non-cumulative). each payday is taxed on its own, ignoring the year so far. Common after starting a new job. It usually rights itself, but check it does not persist past a couple of paydays.
- ⚠ Emergency codes often mean too much tax short-term. HMRC refunds it through your pay once the correct code arrives.
Check your own code
Type any code, this page's and every other format HMRC issues:
Tax-free allowance of about £12,570.00 a year.
- L: you get the standard personal allowance.
Other codes people look up
2026/27 rules, checked 2026-08-28. If your code looks wrong, correct it via your personal tax account on gov.uk, refunds for the current year arrive through your pay automatically.