How to read the standard code
The most common code is 1257L. The number is your tax-free allowance with the last digit removed: 1257 means £12,570. The letter L means you get the standard personal allowance.
On 1257L you pay no income tax on the first £1,047.50 of pay each month.
What each code means
| Code | What it means |
|---|---|
| 1257L | Standard allowance of £12,570. |
| BR | All pay from this job taxed at the basic rate (20%). Common on a second job. |
| D0 | All pay taxed at the higher rate (40%). |
| D1 | All pay taxed at the additional rate (45%). |
| 0T | No personal allowance; pay is taxed through the normal bands. Used when HMRC lacks details or the allowance is used elsewhere. |
| NT | No tax is deducted. |
| K codes | A negative allowance: an amount is added to your taxable pay, usually to collect tax on benefits or unpaid tax. K475 adds £4,750 a year. Tax under a K code cannot exceed half your pay. |
| M / N | Marriage Allowance: M means you received £1,260 of allowance from your partner, N means you transferred it. |
| S prefix | You pay Scottish income tax rates, for example S1257L. |
| C prefix | You pay Welsh income tax rates, for example C1257L (currently the same as England). |
| W1, M1 or X | Emergency code: tax is worked out on each payslip alone, ignoring earlier pay in the year. |
Why your number might not be 1257
A lower number usually means HMRC is collecting tax on a company benefit (a car or medical insurance), on untaxed income, or on tax owed from an earlier year. A higher number means extra allowances, such as Marriage Allowance or job expenses.
If you earn over £100,000 your allowance is reduced, so your code falls below 1257L and reaches 0T at £125,140.
What to do if your code looks wrong
Check your code on your payslip, in the HMRC app or in your personal tax account. If it is wrong, tell HMRC, not your employer: employers can only use the code HMRC sends them. Overpaid tax is refunded through your pay once the code is corrected.