What Is a UK Tax Code?
Your tax code is issued by HMRC and tells your employer how much of your income is tax-free (your tax-free allowance) and therefore how much income tax to deduct from your pay each month. It appears on your payslip and P60.
💷 Key fact: An incorrect tax code can mean you're paying too much or too little tax. Use our salary calculator to see how a different tax code would affect your take-home pay.
The Most Common Tax Code: 1257L
The most common tax code in the UK is 1257L. Breaking this down:
- 1257 – means your tax-free personal allowance is £12,570 (1257 × £10)
- L – means you're entitled to the standard personal allowance
What Tax Code Letters Mean
| Letter | Meaning |
|---|---|
| L | Standard personal allowance (most common) |
| M | Marriage Allowance – received 10% of partner's allowance |
| N | Marriage Allowance – transferred 10% to partner |
| T | HMRC needs more information; special circumstances apply |
| S | Scottish income tax applies (e.g. S1257L) |
| C | Welsh income tax applies |
| BR | Basic Rate – all income taxed at 20%; typically second job |
| D0 | All income taxed at Higher Rate 40%; second job |
| D1 | All income taxed at Additional Rate 45% |
| NT | No Tax – no income tax to be deducted |
| K | Negative allowance – you have untaxed income exceeding your personal allowance (e.g. K500) |
| W1/M1 | Emergency tax code – applied on a weekly or monthly basis only |
| 0T | No personal allowance; often applied when starting a new job without a P45 |
How to Check Your Tax Code
- Check your payslip – your tax code appears on every payslip
- Check your P60 – issued by your employer at the end of each tax year
- Check your HMRC Personal Tax Account at gov.uk/personal-tax-account
- HMRC sends a PAYE coding notice (P2) when your tax code changes
What to Do If Your Tax Code Is Wrong
If you think your tax code is incorrect, contact HMRC directly by phone or through your Personal Tax Account online. Common reasons for wrong tax codes include starting a new job, company benefits, or HMRC having outdated information.