Quick answer
Your tax code tells your employer how much of your pay is tax-free. The numbers are your tax-free allowance divided by 10, and the letter says what kind of code it is. The most common code in 2026/27 is 1257L: £12,570 of tax-free pay with the standard Personal Allowance. A different number usually means HMRC has adjusted it for something, such as a company car, unpaid tax or Marriage Allowance. Check your code on your payslip or in the HMRC app. If it looks wrong, ask HMRC to correct it, because a wrong code means paying the wrong amount of tax every payday.
Most people never look at their tax code until something goes wrong: a payslip with far more tax than usual, a letter from HMRC, or a new job that starts on an emergency code. This guide explains how to read any UK tax code, what each letter means, why codes change and what to do if yours is wrong.
Where to Find Your Tax Code
- Your payslip – usually printed near your name or National Insurance number.
- Your HMRC online account or the HMRC app – shows your current code for each job or pension and lets you see past years.
- A Tax Code Notice (P2) – a letter HMRC sends when your code changes.
- Your P45 or P60 – show the code used when you left a job or at the end of the tax year.
You have a separate tax code for each job and each private or workplace pension.
How to Read the Numbers
Multiply the number by 10 to get the amount you can earn tax-free in the tax year:
HMRC adds allowances or reliefs you are due, takes away anything it needs to tax through your pay, and then drops the last digit. For example:
| Your situation (2026/27) | Working | Tax code |
|---|---|---|
| Standard Personal Allowance | £12,570 | 1257L |
| Claim tax relief for working from home (£6 a week = £312 a year) | £12,570 + £312 = £12,882 | 1288L |
| Uniform flat-rate expense of £60 | £12,570 + £60 = £12,630 | 1263L |
| Company car with a taxable benefit of £3,000 | £12,570 − £3,000 = £9,570 | 957L |
| Receiving Marriage Allowance from your partner | £12,570 + £1,260 = £13,830 | 1383M |
| Transferring Marriage Allowance to your partner | £12,570 − £1,260 = £11,310 | 1131N |
| Income of £110,000 (allowance reduced by £1 for every £2 over £100,000) | £12,570 − £5,000 = £7,570 | 757L |
A lower number means less tax-free pay and more tax each payday. A higher number means more tax-free pay. Read more about the allowance in how the £12,570 Personal Allowance works.
What the Letters Mean
| Letter or code | What it means |
|---|---|
| L | You get the standard tax-free Personal Allowance. |
| M | Your spouse or civil partner has transferred part of their allowance to you (Marriage Allowance). |
| N | You have transferred part of your allowance to your spouse or civil partner. |
| T | HMRC needs to review something in your code, so your employer cannot change it automatically. |
| 0T | No tax-free allowance. All your pay is taxed, starting at the basic rate. Used when your allowance is used up or HMRC does not have enough details. |
| BR | All income from this job or pension is taxed at the basic rate (20%). Common for a second job. |
| D0 | All income from this source is taxed at the higher rate (40%). |
| D1 | All income from this source is taxed at the additional rate (45%). |
| NT | No tax is taken from this income. Used only in specific cases. |
| K (at the start) | You have income that is not being taxed another way, worth more than your tax-free allowance. See below. |
| S (at the start) | Your main home is in Scotland, so Scottish Income Tax rates apply, for example S1257L. |
| C (at the start) | Your main home is in Wales, for example C1257L. Welsh rates are currently the same as in England. |
Scotland has its own versions of the flat-rate codes: SBR (20%), SD0 (21%), SD1 (42%), SD2 (45%) and SD3 (48%). See Scottish Income Tax 2026/27.
K Codes: When You Owe Tax on More Than Your Allowance
A K code means the things HMRC needs to tax through your pay – such as company benefits, State Pension or tax you owe from an earlier year – add up to more than your Personal Allowance. Instead of tax-free pay, the number is added to your taxable pay.
Example from HMRC guidance: with code K475 and a salary of £27,000, £4,750 is added, so tax is worked out on £31,750. That is about £6,350 of Income Tax a year, compared with about £2,886 on 1257L.
There is a safeguard: under a K code, your employer cannot take more than half of your pay before tax in any pay period.
Emergency Tax Codes
If your new employer does not have your P45 or starter checklist, you may be put on an emergency code. It looks like a normal code with W1, M1 or X on the end, for example 1257L M1. Tax is then worked out on each payday on its own, without counting what you have already earned and paid this tax year. That can mean paying too much, especially if you start a job part-way through the year. HMRC normally corrects the code once it has your details, and any overpayment is usually refunded through your pay. Our emergency tax guide explains how to claim back money.
An 0T code costs more than an emergency 1257L code. On £2,500 a month, 0T takes £500 in tax, compared with about £290 under 1257L.
Why Your Tax Code Might Change
- A new benefit at work – a company car, fuel or private medical insurance reduce your code (see what a company car really costs and private health insurance at work).
- Tax you owe from a previous year – HMRC often collects smaller amounts through your code over the following tax year instead of asking for a lump sum.
- Untaxed income – such as rental profit or savings interest above your Personal Savings Allowance.
- Starting the State Pension – the State Pension is taxable but paid without tax taken off, so HMRC usually collects it through the code on your workplace or private pension.
- A second job – your allowance usually goes against your main job, and the second job gets BR or another flat-rate code. See tax with two jobs.
- Income over £100,000 – the Personal Allowance is reduced by £1 for every £2 over £100,000 and disappears at £125,140.
- Claims you make – Marriage Allowance, work expenses or professional subscriptions can increase your code.
HMRC bases many changes on estimates. If your benefits or income have changed, your code may be using an out-of-date figure – one of the most common reasons for a wrong code.
How to Check Your Code Is Right: A Quick Test
- Find the code on your latest payslip.
- Check the letter. L is normal for one job. BR or D0 on your main job, or 0T for more than a month or two, is worth questioning.
- Check the prefix. S if you live in Scotland, C if you live in Wales, none for England or Northern Ireland.
- Check the number. 1257 is standard. If it is lower, look at your Tax Code Notice or HMRC account to see what has been deducted and whether the figures are still correct.
- Check for W1, M1 or X. If one is still there after two or three paydays, ask your employer whether they have sent your starter details to HMRC.
You can then check your take-home pay with our take-home and pay rise calculator, which uses the standard code.
What to Do If Your Tax Code Is Wrong
- Tell HMRC, not just your employer. Employers have to use the code HMRC gives them. You can update details such as your income or benefits in your HMRC online account or the HMRC app, or contact HMRC's Income Tax helpline.
- Have the facts ready – your National Insurance number, employer's PAYE reference (on your payslip or P60) and the figures that are wrong.
- Watch your next payslip. HMRC sends the new code to your employer, and any tax overpaid so far this year is usually refunded through your pay.
- After the tax year ends, HMRC compares what you paid with what you owed. If the totals do not match, you will usually get a P800 calculation showing a refund or an amount owed.
It is your responsibility to make sure you are paying the right tax, so it is worth checking your code whenever it changes and at the start of each tax year in April.
Frequently Asked Questions
What does 1257L mean?
It is the standard tax code for 2026/27. You can earn £12,570 tax-free in the year (about £1,047.50 a month), and L means you get the standard Personal Allowance.
Why is my tax code different from 1257L?
HMRC has adjusted it for something – usually a taxable benefit, tax owed from a previous year, untaxed income, Marriage Allowance or a claim for expenses. Your Tax Code Notice or HMRC account shows the breakdown.
Is BR a bad tax code?
Not on a second job – it is normal, because your allowance is used on your main job. On your only or main job, BR means you get no tax-free allowance there, so check with HMRC.
How long does it take to fix a tax code?
Once HMRC has the right details, it sends the new code to your employer, who uses it on the next payroll it runs. Depending on when payroll closes, this can take one or two paydays.
Will I get a refund if my code was wrong?
If you overpaid during the current tax year, a corrected code normally gives the money back through your pay. For earlier tax years, HMRC usually sends a P800 or you can ask it to check.
Does my tax code affect National Insurance?
No. National Insurance is worked out separately on each payday and does not use your tax code. See our National Insurance guide.