1257L is the standard tax code for 2026/27. The number tells your employer how much you can earn tax-free: add a zero and you get £12,570, which is the Personal Allowance. The L means you get the normal allowance with nothing added or taken away. If you have one job or one pension and nothing unusual going on, 1257L is almost certainly what you should be on.
Your tax code doesn't set your tax rate. It just tells payroll how much of your pay to leave untaxed before the usual 20%, 40% and 45% bands kick in.
Reading the number
Multiply the number by 10 and that's your tax-free pay for the year. A code of 1100L means £11,000 tax-free. A code of 1383M means £13,830.
A lower number usually means HMRC is collecting something through your wages. Common reasons are a company car or private medical insurance, a small amount of tax owed from an earlier year, or untaxed income like rent or interest. A higher number usually means you're getting an extra allowance, such as Marriage Allowance or tax relief on work expenses.
What the letters mean
| Code | What it means |
|---|---|
| L | You get the standard tax-free Personal Allowance. |
| M | Your spouse or civil partner has transferred 10% of their Personal Allowance to you (Marriage Allowance). |
| N | You've transferred 10% of your Personal Allowance to your spouse or civil partner. |
| T | Your code includes other calculations to work out your Personal Allowance, so HMRC will review it if anything changes. |
| 0T | No tax-free allowance at all on this job. Used when your allowance is used up, or when a new employer has no details for you. |
| BR | Everything from this job or pension is taxed at the basic rate, usually because it's a second job. |
| D0 | Everything from this job or pension is taxed at the higher rate (40%). |
| D1 | Everything from this job or pension is taxed at the additional rate (45%). |
| NT | No tax is taken from this income. |
| K | Your deductions are bigger than your allowance, so an amount is added to your taxable pay instead. |
S and C at the front
An S in front of the code (for example S1257L) means you pay Scottish income tax. A C means Welsh rates. Welsh rates are the same as England's for 2026/27, but Scottish rates are not, so if you've moved to or from Scotland and your code hasn't caught up, you could be paying the wrong amount. Scottish codes also have their own flat-rate versions: SBR, SD0, SD1, SD2 and SD3, for the basic, intermediate, higher, advanced and top rates.
K codes
A K code means the things HMRC is collecting add up to more than your Personal Allowance. Multiply the number by 10 and add it to your pay. On K475 with a £27,000 salary, you're taxed as though you earned £31,750. To stop a K code leaving you short, payroll can't take more than half your pay before tax in any one pay period.
Emergency codes: W1, M1 and X
If your code ends in W1, M1 or X (for example 1257L M1), you're on an emergency basis. It usually happens when you start a new job without a P45, start a second job, or start getting a pension.
Normally your tax is worked out on a running total for the year, so any allowance you didn't use in earlier months carries forward. On an emergency code, each payday is treated on its own. You get one-twelfth of the allowance each month (about £1,047.50 on 1257L) and no catch-up for the months before.
Here's what that looks like. You start a new job in November on £2,500 a month, having had no income since April. On 1257L M1, you'd pay 20% on £2,500 − £1,047.50, which is £290.50 that month. On a normal cumulative code you'd have seven or more months of unused allowance (over £7,000) to set against your first pay packet, so you'd pay nothing that month. Once HMRC sends your employer the right code, the overpaid tax usually comes back through payroll.
Why your tax code changes
- You start or stop a company benefit, like a car or health insurance.
- You start a second job or a pension.
- You claim Marriage Allowance, or your partner does.
- You owe tax from an earlier year of less than £3,000 and HMRC collects it through your code.
- HMRC has an estimate of untaxed income, such as savings interest, which may be out of date.
- Your income goes over £100,000 and your Personal Allowance starts to shrink.
How to check and fix your code
Your tax code is on your payslip, and on your P60 and P45. To see why HMRC has given you that code, sign in to your personal tax account on GOV.UK or use the HMRC app. Both show a breakdown of the allowance and every adjustment.
If something's wrong, such as a benefit you no longer have, an old job still showing, or an income estimate that's too high, you can update it in the personal tax account or call HMRC. Don't ask your employer to change your code themselves. They can only use the code HMRC sends them, and the fix has to come from HMRC.
Once HMRC corrects the code, any tax you've overpaid in the current year normally comes back through your wages. For earlier years, HMRC usually sends a P800 calculation showing what you're owed or what you owe.
To see what you should be paying on your salary, use the income tax calculator, or check your full payslip with the take-home pay calculator.
Last reviewed October 2026.