What Is a Tax Code? 1257L and Other Codes Explained
Your tax code tells your employer how much tax-free pay you get. Here is how to read it, and what to do if it is wrong.
What a tax code does
Your employer or pension provider uses your tax code to work out how much Income Tax to take from your pay. HMRC decides your code and tells your employer. You get a separate code for each job or pension.
What 1257L means
For the 2026/27 tax year the standard code is 1257L. The number is your tax-free allowance divided by ten, so 1257 means a Personal Allowance of £12,570. The letter L means you are entitled to the standard Personal Allowance.
If HMRC reduces your allowance, for example because you have a company benefit such as medical insurance, the number goes down. A £1,570 benefit would take your code from 1257L to 1100L.
Tax code letters
| Letter | What it means |
|---|---|
| L | You get the standard Personal Allowance. |
| M | You have received 10% of your partner’s Personal Allowance through Marriage Allowance. |
| N | You have transferred 10% of your Personal Allowance to your partner through Marriage Allowance. |
| T | Your allowance includes other calculations. |
| 0T | Your Personal Allowance has been used up, or your employer does not have enough information about you. |
| BR | All income from this job is taxed at the basic rate, usually where you have more than one job. |
| D0 / D1 | All income from this job is taxed at the higher (D0) or additional (D1) rate. |
| K | You have untaxed income above your allowance, so the calculation works differently. |
Scotland and Wales
A prefix shows where you pay tax. S means Scottish income tax rates apply (for example S1257L), and C means Welsh rates apply (C1257L). Wales uses the same rates as England and Northern Ireland.
What if my tax code is wrong?
You can see your code on your payslip, in the HMRC app, in your personal tax account or on a tax code notice. If you think it is wrong, tell HMRC. A wrong code can mean you pay too much or too little tax during the year. If you have been underpaying, HMRC may collect it later through your code or a bill. Use our take-home pay calculator to see what your pay should look like with the standard code.
This guide is general information, not financial or legal advice. Rates checked 8 October 2026 against GOV.UK.