Tax codes explained: what the letters and numbers mean

Your tax code tells your employer or pension provider how much of your pay to treat as tax-free. HMRC sets it, based on what it knows about your allowances, benefits and other income. If that information is out of date, the code will be wrong, and so will your tax.

The standard code: 1257L

For most people with one job or pension, the 2026/27 tax code is 1257L:

• 1257 means £12,570 of tax-free pay for the year (the number is the allowance divided by 10)
• L means you get the standard tax-free Personal Allowance

The code has been 1257L since 2021/22 because the Personal Allowance is frozen. Your employer spreads the allowance across the year: with 1257L you get about £1,048 a month (or £242 a week) tax-free.

What the letters mean

In Scotland the BR, D0 and D1 equivalents are SBR, SD0, SD1, SD2 and so on, reflecting Scottish bands.

Prefixes: S and C

• S at the start (for example S1257L) means you are a Scottish taxpayer and Scottish Income Tax rates apply to your earnings.
• C at the start (for example C1257L) means you are a Welsh taxpayer. Welsh rates currently match those in England.

If you have moved between Scotland and the rest of the UK, check the prefix has changed. Your residence on most days of the tax year decides which rates apply.

Why your number might be different

HMRC adjusts the number up or down for allowances and deductions:

K codes

A K code (for example K450) means your deductions are £4,500 more than your allowances, so £4,500 is added to your taxable pay. This happens when you have large benefits in kind, such as an expensive company car, or untaxed income. Tax deducted under a K code cannot exceed 50% of your pay in any pay period; any remaining tax may be collected later.

Emergency codes

Codes ending in W1, M1 or X (for example 1257L M1) are emergency codes. They mean tax is calculated on each payment separately rather than cumulatively, so you do not get any unused allowance from earlier in the year. They are used when a new employer does not have your details. See emergency tax codes.

Second jobs and pensions

Your Personal Allowance normally goes to your main job or pension. A second job usually gets BR, so all its pay is taxed at 20%. If your main job does not use all your allowance, you can ask HMRC to split it between jobs. Pensioners with a State Pension and a workplace pension often have a reduced code on the workplace pension to collect the tax due on the State Pension.

How to check and fix your tax code

• Check your code on your payslip, P60, or in your HMRC online account or the HMRC app.
• Look at the explanation HMRC gives for how the code was worked out.
• If something is wrong, such as a benefit you no longer have or an estimate of income that is out of date, update it with HMRC online, in the app or by phone. HMRC then sends a new code to your employer.
• Your employer cannot change your code without an instruction from HMRC.

Overpaid tax is usually refunded through your pay once the code is corrected, or by HMRC after the end of the tax year.

Frequently asked questions

What is the tax code for 2026/27?

1257L for most people with one job or pension, giving £12,570 of tax-free pay.

What does the M in my tax code mean?

You receive Marriage Allowance from your spouse or civil partner, which adds £1,260 to your tax-free amount (code 1383M in 2026/27).

Why is my tax code BR?

BR means all your income from that job or pension is taxed at 20%, usually because your Personal Allowance is used by another job or pension. If it is your only job, contact HMRC to correct it.

What is a K tax code?

It means you have more taxable benefits or adjustments than tax-free allowances, so an amount is added to your taxable pay. Tax under a K code is limited to 50% of each payment.

What does 0T mean?

You have no Personal Allowance for that job or pension, so all of it is taxed. It is common when your allowance has been used up, or as an emergency code when your employer lacks your details.