Last updated: 19 October 2026
Your tax code tells your employer or pension provider how much tax-free pay to give you and how to tax the rest. If the code is wrong, you can pay too much or too little tax for months without noticing. This guide explains how UK tax codes work for the 2026/27 tax year, what the numbers and letters mean, the most common codes, and how to fix a code that looks wrong.
What Are UK Tax Codes?
HMRC issues a tax code for each job or pension you have. Your employer uses it through PAYE to work out how much Income Tax to deduct each payday. The code is made up of numbers (your tax-free amount) and letters (your circumstances).
How Do UK Tax Codes Work?
The Number Part: Your Tax-Free Allowance
HMRC starts with your Personal Allowance, which is £12,570 for 2026/27. The allowance is frozen at this level until 5 April 2031. HMRC then deducts anything that reduces it (for example taxable company benefits or untaxed income) and adds anything that increases it (for example the Marriage Allowance or some job expenses). The result is divided by 10 to give the number in your code.
The Letter Part: Your Circumstances
The letter tells your employer how to apply the number. “L” means you get the standard Personal Allowance; other letters cover Marriage Allowance, second jobs, emergency codes and Scottish or Welsh taxpayers.
Tax Code Example
You are entitled to the £12,570 Personal Allowance, but you also have private medical insurance through work worth £1,570 a year. HMRC deducts the benefit, leaving £11,000 of tax-free pay, so your code becomes 1100L.
What Is the Normal Tax Code in the UK?
The standard tax code for 2026/27 is 1257L. It is used for most people with one job or pension and no untaxed income or company benefits. Scottish taxpayers have S1257L and Welsh taxpayers C1257L.
If your income is over £100,000, your Personal Allowance is reduced by £1 for every £2 above that level and is lost entirely at £125,140, so your code will be lower than 1257L.
Most Common UK Tax Codes for 2026/27
| Code | What it means |
|---|---|
| 1257L | Standard Personal Allowance of £12,570 |
| 1257L W1 / M1 or 1257L X | Emergency code: tax worked out on each week’s or month’s pay on its own (non-cumulative) |
| BR | All income from this job or pension taxed at the 20% basic rate (often a second job) |
| D0 | All income taxed at the 40% higher rate |
| D1 | All income taxed at the 45% additional rate |
| 0T | No tax-free allowance, either because it is used up or your employer lacks your details |
| NT | No tax deducted from this income |
| 1383M | You have received 10% (£1,260) of your partner’s Personal Allowance through Marriage Allowance |
| 1131N | You have transferred £1,260 of your Personal Allowance to your partner |
| K codes (e.g. K475) | Your deductions exceed your allowance, so an amount is added to your taxable pay |
| S / C prefix | Scottish or Welsh rates of Income Tax apply |
With a K code, your employer cannot deduct more than 50% of your pay in tax in any pay period.
What Is My Tax Code?
You can find your tax code on your payslip, your P60 or P45, in your personal tax account on GOV.UK, or in the HMRC app. You can also use our tax code checker to see what your code means.
Why Your Tax Code Might Change
- You start a new job or pension, or have more than one.
- You start or stop receiving a company car, medical insurance or other benefits.
- HMRC is collecting tax you underpaid in an earlier year, or adjusting for untaxed savings or rental income.
- You claim Marriage Allowance or job expenses such as professional fees or uniform costs.
- Your income goes above £100,000, or you start receiving the State Pension.
Common Tax Code Problems and How to Fix Them
1. Being Put on an Emergency Tax Code
If your new employer does not have a P45 or completed starter checklist, you may be put on an emergency tax code. Give your employer your P45 or starter checklist and HMRC will usually issue the correct code within a few pay periods. Any overpaid tax is normally refunded through your pay.
2. Wrong Code for a Second Job or Pension
Your allowance is normally given against your main job, with BR on the second. If the split is wrong, ask HMRC to move your allowance between jobs.
3. Company Benefits Not Included or Out of Date
If a benefit has ended, or the amount is wrong, update HMRC through your personal tax account so your code stops reducing your allowance.
4. Changes in Your Personal Life
Marriage, divorce, a change in income or moving between Scotland, Wales and England can all affect your code. Tell HMRC when your circumstances change.
5. Scottish or Welsh Codes Not Applied
If you have moved, check that your code carries the right S or C prefix. Your address with HMRC decides which rates apply.
Why It Is Important to Check Your Tax Code
Employers must use the code HMRC sends them, even if it is wrong. Checking your code each April and whenever you change jobs is the quickest way to avoid an unexpected bill or to get a refund sooner.
How to Check and Update Your Tax Code
- Sign in to your HMRC personal tax account or the HMRC app.
- Check the code and the explanation of how it was worked out.
- Use the “check or update your Income Tax estimate” option if your income, benefits or jobs are wrong.
- Alternatively, contact HMRC by phone or webchat.
What Is the Tax Code for Students?
Students working part-time are usually on 1257L, the same as anyone else. If you start a job without a P45, complete the starter checklist and choose the statement that matches your situation, otherwise you may be put on an emergency code or BR.
Frequently Asked Questions
What is the tax code for 2026/27?
The standard tax code for 2026/27 is 1257L, based on a Personal Allowance of £12,570.
Why do I have a BR tax code?
BR means all income from that job or pension is taxed at 20%. It is normal for a second job, but if it is on your only or main job you may be overpaying.
What does W1 or M1 mean after my tax code?
It means an emergency, non-cumulative code. Tax is worked out on each payment on its own, so any tax-free allowance not used earlier in the year is not given back until the code is corrected.
Can I get a refund if my tax code was wrong?
Yes. If you paid too much, HMRC will usually refund it through your pay or after the tax year ends. You can claim back overpaid tax for up to four previous tax years. See our guide on how to claim a tax refund.
How Can Accotax Help?
If your tax code keeps changing, you have several jobs or pensions, or you think you have overpaid, our tax refund accountants can check your codes and deal with HMRC for you. Contact us to book a call.
