UK Tax Code Checker
Enter your tax code to find out what it means and check if it's correct
Last updated: March 2026 · Reflects 2025/26 tax year
Enter Your Tax Code
Find your tax code on your payslip, P45, P60, or HMRC coding notice (P2). It looks like 1257L, S1257L, BR, or K475.
Enter your tax code above
Type your tax code from your payslip, P45, P60, or HMRC coding notice and click "Check" to see what it means.
How HMRC Calculates Your Tax Code
HMRC starts with the standard Personal Allowance (£12,570 for 2025/26) and adjusts it based on your circumstances:
| Adjustment | Effect |
|---|---|
| Company car / fuel benefit | Reduces allowance |
| Private medical insurance | Reduces allowance |
| Underpaid tax from prior year | Reduces allowance |
| State pension income | Reduces allowance |
| Marriage Allowance (recipient) | Increases allowance |
| Blind Person's Allowance | Increases allowance |
Your P2 coding notice from HMRC lists every adjustment. Check it at GOV.UK.
Common Tax Code Mistakes
- Wrong code after changing jobs — your new employer may put you on an emergency code (W1/M1) until they receive your P45
- Marriage Allowance not applied — if eligible, you could be missing out on up to £252/year in tax savings
- Old benefit still coded — if you no longer have a company car or medical insurance, your code may still reflect the old benefit
- Double-counted income — HMRC may overestimate your other income sources (savings interest, rental income), reducing your allowance too much
- BR on your only job — if this is your only employment, you should have a numeric code, not BR
If your tax code seems wrong, call HMRC on 0300 200 3300 or check online via your Personal Tax Account.
Emergency Tax Codes Explained
Emergency tax codes have a W1, M1, or X suffix. They mean your tax is calculated on a non-cumulative basis — each pay period is treated independently instead of spreading your allowance over the year.
| Suffix | Meaning |
|---|---|
| W1 | Week 1 basis (weekly paid) |
| M1 | Month 1 basis (monthly paid) |
| X | Non-cumulative (any frequency) |
Common causes:
- Starting a new job without a P45
- Starting your first job ever
- Receiving a new taxable benefit
- HMRC hasn't finished processing your details
You may overpay tax on an emergency code. Once HMRC issues your correct code, any overpaid tax is usually refunded through your payroll automatically. If not, you can claim a tax refund from HMRC.
Scottish & Welsh Tax Codes
If you live in Scotland, your tax code starts with S (e.g. S1257L). If you live in Wales, it starts with C (e.g. C1257L). Your employer uses the prefix to apply the correct tax rates.
| Scottish Band | Rate |
|---|---|
| Starter rate (£12,571–£15,397) | 19% |
| Basic rate (£15,398–£27,491) | 20% |
| Intermediate (£27,492–£43,662) | 21% |
| Higher rate (£43,663–£75,000) | 42% |
| Advanced rate (£75,001–£125,140) | 45% |
| Top rate (over £125,140) | 48% |
Welsh rates currently match England & NI rates. See the full comparison in our Scottish Tax vs English Tax blog post, or calculate your take-home pay with our Take-Home Pay Calculator.
How This Tool Works
- Parses your tax code to identify the prefix (S for Scotland, C for Wales), number, and letter suffix
- Multiplies the number by 10 to calculate your Personal Allowance (e.g. 1257 × 10 = £12,570)
- Decodes the letter suffix to explain your tax situation (L = standard, M/N = Marriage Allowance, etc.)
- Identifies special codes (BR, D0, D1, NT, K codes) and explains what they mean
- Detects emergency tax suffixes (W1, M1, X) and warns if you may be overpaying
- Shows the applicable tax bands for your region (English, Scottish, or Welsh rates)
Full Tax Code Reference
| Code/Letter | Meaning |
|---|---|
| 1257L | Standard code — £12,570 tax-free allowance |
| L | Standard Personal Allowance |
| M | Marriage Allowance — you received a transfer |
| N | Marriage Allowance — you transferred yours |
| T | HMRC reviewing your tax situation |
| S | Scottish tax rates apply |
| C | Welsh tax rates apply |
| K | Negative allowance — extra tax owed |
| BR | All income taxed at 20% (basic rate) |
| D0 | All income taxed at 40% (higher rate) |
| D1 | All income taxed at 45% (additional rate) |
| NT | No tax deducted |
| 0T | No Personal Allowance, progressive bands |
| W1/M1/X | Emergency — non-cumulative basis |
For the full official list, see GOV.UK — Tax codes.
Tax Code FAQs
What does my tax code mean?
Your tax code tells your employer how much tax to deduct from your pay. The numbers represent your tax-free Personal Allowance (multiply by 10), and the letters indicate your circumstances. For example, 1257L means you have the standard £12,570 Personal Allowance.
What is the most common tax code?
The most common tax code for 2025/26 is 1257L. It means you have the standard Personal Allowance of £12,570. If you live in Scotland, the equivalent is S1257L, and in Wales it's C1257L.
What does the L in my tax code mean?
The letter L means you're entitled to the standard tax-free Personal Allowance. It's the most common suffix. Other letters include M (Marriage Allowance recipient), N (Marriage Allowance transferor), and T (items HMRC needs to review).
What is an emergency tax code?
An emergency tax code (shown with W1, M1, or X suffix) means your tax is calculated on a non-cumulative basis — each pay period is treated independently. This often happens when starting a new job without a P45. You may overpay tax and can claim a refund from HMRC.
What does a K tax code mean?
A K code means your tax-free allowance has been reduced below zero, so HMRC is collecting extra tax through your wages. The number after K, multiplied by 10, shows the extra amount being taxed. Common reasons include company car benefits, medical insurance, or underpaid tax from previous years.
How do I check if my tax code is correct?
Check your P2 coding notice from HMRC, which explains how your code was calculated. You can also check online via your HMRC Personal Tax Account at GOV.UK. If your allowance seems wrong, contact HMRC on 0300 200 3300.
What is a Scottish tax code?
Scottish tax codes start with an S prefix (e.g. S1257L). This means you pay Scottish income tax rates, which have six bands from 19% to 48% for 2025/26. Your tax code is based on where you live, not where you work.
Disclaimer
This tool decodes UK tax codes based on standard HMRC rules for the 2025/26 tax year. Individual circumstances may vary and HMRC may have specific reasons for your tax code that aren't captured here. For complex tax situations, please consult a qualified accountant or contact HMRC directly. This tool is for informational purposes only and should not be considered tax advice.