Key takeaways
- 1257L means a £12,570 personal allowance at the standard 2026/27 bands — take the digits, add a zero, and you have your tax-free allowance.
- On a £35,000 salary, 1257L gives £12,570 tax-free and taxes the remaining £22,430 at 20% — income tax £4,486.00, take-home pay £28,719.60 a year.
- BR, D0 and D1 are the codes for second jobs: your allowance is already used up on your main job, so the second income is taxed from the first pound.
- You do not fix a tax code by asking your employer — the fix goes through HMRC, and any tax overpaid in the same tax year is normally repaid through your pay automatically.
1257L means you get the standard £12,570 personal allowance, taxed at the normal 2026/27 bands — it is the code most UK employees should be on, and if yours is different, it is worth two minutes of your time to find out why.
Your tax code sits on every payslip you will ever receive, usually near the top, in a small box that is easy to ignore. It is the instruction your employer follows when working out how much income tax to take from your pay, and a wrong code is the single most common reason a payslip looks wrong. This article takes the code apart letter by letter, shows you what it does to your pay in pounds, and tells you how to tell whether yours is right.
Check yours now
Type your tax code in the take-home pay calculator and see your take-home pay change. The full 2026/27 rates page has every band and threshold behind the figures below.
Breaking 1257L apart
The number is the allowance. Take the digits, add a zero, and you have your tax-free personal allowance for the year: 1257 becomes £12,570. That is the amount you can earn before income tax starts. The letter tells HMRC which version of the allowance applies. L is the standard one — the basic personal allowance, for most people, with no adjustments. Other letters mean something has been moved: M means you have received £1,260 of your partner's allowance through the Marriage Allowance, N means you have given £1,260 of yours away, and T means your code includes other calculations HMRC has not spelled out in the code itself.
So 1257L is the default, and it is the default for a reason: it suits the majority of people with one job, no taxable benefits, and no untaxed income HMRC needs to collect through their pay. If any of those things change — a company car, a second income, a tax bill from an earlier year — HMRC will usually change the code rather than send you a bill. That is why codes drift over time, and why the code on this month's payslip may not be the one on last year's.
What 1257L does to your pay
On a £35,000 salary with no pension and no student loan, 1257L gives you £12,570 tax-free and taxes the remaining £22,430 at the 20% basic rate. Income tax is £4,486.00.
National Insurance, which the tax code does not touch, is £1,794.40 — 8% of the pay between £12,570 and £35,000. Take-home pay is £28,719.60 a year, or £2,393.30 a month.
Add the standard auto-enrolment pension and the numbers shift: the pension is £1,438.00 a year (5% of qualifying earnings of £28,760), taxable pay falls to £20,992, income tax falls to £4,198.40, National Insurance stays at £1,794.40, and take-home pay is £27,569.20 a year. The tax code has not changed — the pension has just reduced the pay the code is applied to. That distinction matters, because people often blame their tax code for a change that was really caused by a pension or a benefit.
The same code at other salaries shows the pattern clearly:
| Salary | Taxable pay | Income tax | National Insurance | Take-home / year |
|---|---|---|---|---|
| £20,000 | £7,430 | £1,486.00 | £594.40 | £17,919.60 |
| £25,000 | £12,430 | £2,486.00 | £994.40 | £21,519.60 |
| £30,000 | £17,430 | £3,486.00 | £1,394.40 | £25,119.60 |
| £35,000 | £22,430 | £4,486.00 | £1,794.40 | £28,719.60 |
| £40,000 | £27,430 | £5,486.00 | £2,194.40 | £32,319.60 |
Every row uses 1257L, no pension, no student loan. The pattern to notice is the regularity: each extra £5,000 of salary adds exactly £1,000 of income tax and £400 of National Insurance at these levels, because all of it sits in the 20% band and the 8% National Insurance band. That regularity breaks the moment you cross £50,270 — the higher rate — or £100,000, where the allowance itself starts to shrink. Both are covered in the £100,000 tax trap and on the UK tax rates 2026/27 page.
The other codes you are likely to see
Not everyone is on 1257L, and most of the other codes are perfectly legitimate. Here are the ones that turn up most often, with what each one does to a £50,000 salary so you can compare them directly:
| Code | Meaning | Income tax on £50,000 |
|---|---|---|
| 1257L | Standard £12,570 allowance | £7,486.00 |
| S1257L | Scottish taxpayer, same allowance, Scottish bands | £8,982.05 |
| BR | Basic rate — flat 20% on everything, no allowance | £10,000.00 |
| D0 | Higher rate — flat 40% on everything, no allowance | £20,000.00 |
| D1 | Additional rate — flat 45% on everything, no allowance | £22,500.00 |
| 0T | No personal allowance at all | £12,460.00 |
| NT | No tax to pay on this income | £0.00 |
BR, D0 and D1 are the codes for second jobs and second incomes: your allowance is already used up on your main job, so the second income is taxed from the first pound at a flat rate. That is why a second job can feel so heavily taxed — it is not a penalty, it is the absence of a second allowance, and it is usually right. 0T is the code HMRC uses when it does not know your allowance yet, or when you have used it all elsewhere. NT is rarer: it means no income tax is due on that particular income, usually because it is already taxed another way.
Two more deserve a mention. K codes work backwards: a K500 code adds £5,000 to your taxable pay instead of giving you an allowance, which usually means you owe tax on benefits or income HMRC is collecting through your pay. On a £50,000 salary, K500 gives income tax of £14,460.00 — more than BR, because the £5,000 is added on top of the full salary and part of it is taxed at 40%. And M codes: 1383M means an allowance of £13,830 — your own £12,570 plus £1,260 transferred from your partner under the Marriage Allowance. On a £35,000 salary that cuts income tax from £4,486.00 to £4,234.00 and lifts take-home pay to £28,971.60 a year. If your partner earns under the personal allowance and you are a basic-rate taxpayer, that transfer is usually worth claiming.
Scottish taxpayers have the same numbers with an S in front: S1257L is the Scottish version of 1257L, with the same £12,570 allowance but Scotland's six bands. On a £35,000 salary the Scottish tax is £4,501.07 rather than £4,486.00, and take-home pay is £28,704.53 rather than £28,719.60 — a £15.07-a-year difference at that salary, which grows sharply higher up the scale. The Scottish income tax calculator compares the two at any salary.
When your code is wrong
The most expensive wrong code is the one you never notice. Here are the signs. First, the emergency codes: if you start a new job and your first payslip shows 0T, BR, or a code ending in W1 or M1, you are probably on an emergency basis — HMRC is taxing you as if your pay were spread evenly across the year, without your proper allowance. That usually fixes itself once HMRC receives your details, and any overpaid tax comes back through your pay or a refund, but it can take a month or two, and it is worth checking rather than assuming.
Second, a code that does not match your life. If you have one job, no benefits in kind, and no untaxed income, and your code is anything other than 1257L — or S1257L in Scotland — ask why. If you left a job and started another, check the code followed you: an old employer's code, or a BR code from a second job that has become your only job, will quietly over-tax you month after month. If you received Marriage Allowance, your code should end in M and your partner's in N; if neither of you has the letter, the transfer has not happened.
Third, the arithmetic test. Take your gross pay for the year, subtract the allowance your code implies, and check the tax against the bands. On 1257L at £35,000, that is £35,000 minus £12,570, which is £22,430, all at 20%, which is £4,486.00. If your payslip shows something very different and there is no pension, benefit, or student loan to explain it, the code is the first suspect. Run the same check in the take-home pay calculator — type your code in exactly as it appears and compare the result with your payslip line by line.
How to get a wrong code fixed
You do not fix a tax code by asking your employer to change it — your employer can only apply the code HMRC sends them. The fix goes through HMRC: sign in to your Personal Tax Account on GOV.UK and check the code it holds for you, or call HMRC if the online record does not match your payslip. Tell them what has changed — a job ended, a benefit stopped, a second income finished — and they will issue a new code to your employer. The correction usually applies from the next pay run, and any tax you overpaid in the same tax year is normally repaid through your pay automatically. If the overpayment is from an earlier tax year, HMRC will usually send a refund or a calculation letter instead.
Two practical habits will save you more than any single fix. Check your code on the first payslip of every tax year — codes are often reissued in April, and that is when mistakes slip in. And check it again whenever anything changes: a new job, a pay rise that crosses £100,000, a company car, or a partner's Marriage Allowance claim. Each of those is a moment HMRC recalculates, and each is a moment a wrong number can arrive. The code itself is only four or five characters; the amount of money it controls is not.
Run the arithmetic test on your own pay
Type your code in exactly as it appears in the take-home pay calculator and compare the result with your payslip line by line.
Rates: GOV.UK — last checked 5 November 2026. This site is not affiliated with HMRC or GOV.UK.