Tax code 1257L is the most common tax code in the UK. It tells your employer you are entitled to the standard £12,570 Personal Allowance, so the first £12,570 you earn in the 2026/27 tax year is free of Income Tax. If you have one job, no company benefits and earn under £100,000, tax code 1257L is usually correct.
What the numbers and letter in tax code 1257L mean
- 1257 is your tax-free allowance divided by 10: £12,570.
- L means you get the standard Personal Allowance.
- S at the start (S1257L) means you pay Scottish Income Tax; C (C1257L) means Welsh rates.
HMRC lists every letter on its official tax codes page.
How your employer uses the code
Payroll spreads the allowance over the year. Paid monthly, you get £1,047.50 of tax-free pay each month; paid weekly, about £241.73 a week. Tax is then charged on the rest at your band rates. Under a normal (cumulative) code, payroll looks at your pay for the whole year to date, so any unused allowance from earlier months is carried forward.
Monthly Income Tax on common salaries with tax code 1257L (no pension):
| Salary | Gross per month | Income Tax (1257L) | Income Tax (S1257L) |
|---|---|---|---|
| £20,000 | £1,667 | £124 | £121 |
| £30,000 | £2,500 | £291 | £288 |
| £45,000 | £3,750 | £541 | £574 |
| £60,000 | £5,000 | £953 | £1,099 |
National Insurance is separate and does not depend on your tax code.
Emergency tax codes: W1, M1 and X
When you start a new job without a P45, your employer may use 1257L W1 (weekly pay), 1257L M1 (monthly pay) or 1257L X. These are “non-cumulative”: each payslip gets one week’s or one month’s allowance, and earlier months are ignored.
- If you have worked all year at a steady wage, you usually pay about the right tax.
- If you had a gap without work, you lose the unused allowance from those months until HMRC updates your code.
- Any overpayment is normally refunded through your payslip once the code is corrected, or after the tax year ends.
The gov.uk emergency tax codes page explains what to do.
Worked example: starting a job in October
Imagine you start a £30,000 job in October (month 7 of the tax year) after six months without income. Your first monthly payslip is £2,500 gross.
- Tax code 1257L (cumulative): payroll gives you seven months of allowance, £7,332.50, which is more than you have earned so far. Income Tax on the payslip: £0.
- Tax code 1257L M1 (emergency): only one month of allowance, £1,047.50, is used. Income Tax: £290.50.
The cumulative code gets the year right automatically, but on M1 the unused allowance from the months without work is not given back until HMRC updates your code or refunds you after the year ends. That is why it pays to give your new employer your P45 or complete the starter checklist quickly.
Why your code might change during the year
- You receive a company car, private medical insurance or another taxable benefit.
- You owe tax from a previous year that HMRC collects through your code (up to certain limits).
- You start a second job or begin receiving a pension.
- You claim job expenses or Marriage Allowance.
- Your income goes above £100,000.
Other codes you might see
| Code | What it means |
|---|---|
| BR | All income taxed at 20%, usually a second job or pension. |
| D0 / D1 | All income taxed at 40% / 45%. |
| 0T | No allowance: tax from the first pound. |
| NT | No tax deducted. |
| K (e.g. K475) | Untaxed income or benefits exceed your allowance, so an amount is added to taxable pay. |
| M / N | Marriage Allowance received / transferred. |
The cost of a wrong code can be large. On £30,000, tax code 1257L gives £3,486 of Income Tax a year, while 0T would take about £6,000, a difference of £2,514.
Tax codes above £100,000
The Personal Allowance falls by £1 for every £2 of income over £100,000. HMRC lowers your code to match:
| Income | Allowance | Typical code |
|---|---|---|
| £105,000 | £10,070 | 1007L |
| £110,000 | £7,570 | 757L |
| £120,000 | £2,570 | 257L |
From £125,140 the allowance is gone entirely. Our £100k tax trap guide shows the effect on take-home pay.
How to check your tax code
- Look at your payslip or P45.
- Sign in to your personal tax account on gov.uk or the HMRC app, which also shows how the code was calculated.
- Check that the employers, benefits and income listed are right.
- If something is wrong, tell HMRC; you can check your Income Tax online.
Takeaway
For most employees with one job, tax code 1257L is simply the £12,570 allowance at work. An X, W1 or M1 after it, a BR or 0T code, or a code that changes suddenly are all worth checking. See what your salary should be with the UK take-home pay calculator or our UK Income Tax rates guide.
Frequently asked questions
What does tax code 1257L mean?
You get the standard £12,570 Personal Allowance. The number is the allowance divided by 10, and L means you get the normal tax-free amount.
Is 1257L an emergency tax code?
Not on its own. It becomes an emergency code when followed by W1, M1 or X, which means your tax is worked out on each payslip separately.
Why is my tax code not 1257L?
HMRC adjusts codes for things like company benefits, untaxed income, tax owed from earlier years, a second job or income over £100,000.
What is the difference between 1257L and S1257L?
Both give the same £12,570 allowance. The S means your income is taxed at Scottish rates because your main home is in Scotland.
How do I change a wrong tax code?
Contact HMRC through your personal tax account, the HMRC app or by phone. Your employer cannot change it without HMRC’s instruction.
Estimates for information only, not tax advice.
