Quick Tax Code Lookup
What is a Tax Code?
A tax code is a combination of numbers and letters (e.g., 1257L) used by your employer or pension provider to calculate the amount of Income Tax to deduct from your pay or pension.
The number in your tax code (multiplied by 10) represents your tax-free Personal Allowance. For example, 1257 means £12,570 tax-free income.
The letter(s) tell your employer how to adjust your allowance for different circumstances.
⚠️ If your tax code is wrong, you could be paying too much or too little tax. Check it regularly!
Tax Code 1257L Explained
1257L is the most common tax code in the UK for the 2025/26 tax year. If you have one job and no taxable benefits, this is likely your code.
Breaking it down:
- 1257 = Your tax-free Personal Allowance is £12,570 (1257 × 10)
- L = You're entitled to the standard tax-free Personal Allowance
With 1257L, your first £12,570 of annual income is tax-free. You then pay 20% tax on earnings between £12,571 and £50,270, and 40% on earnings above that.
Tax Code Letters Explained
L - Standard Personal Allowance
You're entitled to the standard tax-free Personal Allowance (£12,570 for 2025/26). This is the most common letter.
M and N - Marriage Allowance
Used when transferring Personal Allowance between married couples or civil partners.
- M: You've received 10% of your partner's allowance (code becomes 1394M)
- N: You've transferred 10% of your allowance to your partner (code becomes 1120N)
T - HMRC Review Required
HMRC needs to review your tax situation to calculate your allowance. This might be due to estimated income over £100,000 or other complex circumstances.
0T - No Personal Allowance
You have no tax-free allowance. All income is taxed. Common reasons:
- Your allowance is used up elsewhere
- You earn over £125,140 (Personal Allowance is fully withdrawn)
- You haven't provided employer with correct details
S - Scottish Tax Codes
If you live in Scotland, your code starts with S (e.g., S1257L). Scotland has different tax rates:
- 19% Starter rate: £12,571 - £14,876
- 20% Basic rate: £14,877 - £26,561
- 21% Intermediate rate: £26,562 - £43,662
- 42% Higher rate: £43,663 - £75,000
- 45% Advanced rate: £75,001 - £125,140
- 48% Top rate: Over £125,140
C - Welsh Tax Codes
If you live in Wales, your code starts with C (e.g., C1257L). Currently, Welsh tax rates are the same as England and Northern Ireland.
Second Job & Pension Tax Codes: BR, D0, D1
If you have multiple income sources, your Personal Allowance is usually applied to your main job. Additional jobs or pensions use these codes:
Example: You earn £35,000 from your main job (code 1257L) and £5,000 from a second job (code BR). Your main job uses your £12,570 allowance, so your second job income is taxed at 20% from the first pound.
K Tax Codes Explained
A K code (e.g., K100, K500) means you have income or benefits that need to be taxed, but the value exceeds your Personal Allowance.
Instead of giving you tax-free pay, a K code adds to your taxable income.
Common reasons for K codes:
- Company car benefit exceeds your Personal Allowance
- Private medical insurance provided by employer
- State Pension plus employment income
- Unpaid tax from previous years being collected
Example: K100 means £1,000 is added to your taxable income (100 × 10). If you earn £30,000, you're taxed as if you earned £31,000.
Emergency Tax Codes: W1, M1, X
If you see W1, M1, or X after your tax code (e.g., 1257L W1 or 1257L M1), you're on emergency tax.
Emergency tax means your pay is taxed on each pay period alone, without considering your year-to-date earnings or unused Personal Allowance.
Why you might be on emergency tax:
- Started a new job without giving your P45
- First job and didn't complete a Starter Checklist
- Returned to work after a gap in employment
- Receiving a new pension
How to fix it:
Give your P45 to your new employer, or complete the Starter Checklist. HMRC will update your tax code and any overpaid tax will usually be refunded automatically in your next payslips.
How to Check Your Tax Code
You can find your tax code on:
- Your payslip (usually near your National Insurance number)
- Your P60 (end of year certificate)
- Your P45 (if you recently left a job)
- Your Personal Tax Account on GOV.UK
- HMRC app
If you think your tax code is wrong, contact HMRC directly. Your employer cannot change it without an instruction from HMRC.
Complete Tax Code Reference
| Code/Letter | Meaning |
|---|---|
| L | Standard Personal Allowance |
| M | Marriage Allowance - received 10% extra |
| N | Marriage Allowance - transferred 10% away |
| T | HMRC review required |
| 0T | No Personal Allowance |
| K | Deductions exceed allowance (adds to taxable income) |
| BR | All income taxed at 20% |
| D0 | All income taxed at 40% |
| D1 | All income taxed at 45% |
| NT | No tax deducted |
| S (prefix) | Scottish tax rates apply |
| C (prefix) | Welsh tax rates apply |
| W1/M1/X (suffix) | Emergency/non-cumulative tax basis |
Frequently Asked Questions
What does tax code 1257L mean?
1257L is the standard tax code for 2025/26. The 1257 means your Personal Allowance is £12,570 (1257 × 10), and L means you're entitled to the standard allowance. This is the most common code for people with one job and no taxable benefits.
What does tax code D0 mean?
D0 means all income from this source is taxed at 40% (higher rate). It's typically used for second jobs or pensions where your Personal Allowance is already being used by your main income. You receive no tax-free allowance on this income.
Why is my tax code different from 1257L?
Your code might differ if: you have taxable benefits (company car, medical insurance), you have multiple jobs, you receive state pension, you've transferred Marriage Allowance, you earn over £100k (Personal Allowance reduces), or you have unpaid tax from previous years.
What should I do if my tax code is wrong?
Contact HMRC directly to update your tax code. You can do this online via your Personal Tax Account, by phone, or by post. Your employer cannot change your tax code without instructions from HMRC. If you've overpaid tax, you can claim a refund.
What is a K tax code?
A K code means your taxable benefits or income exceed your Personal Allowance. Instead of receiving tax-free pay, the excess is added to your taxable income. For example, K100 adds £1,000 to your taxable earnings. This commonly happens with company car benefits or when receiving state pension alongside employment.
What does W1 or M1 mean in my tax code?
W1 (Week 1) or M1 (Month 1) means you're on emergency tax. Each pay period is calculated independently, ignoring previous earnings. This often happens when starting a new job without a P45. The overpaid tax is usually automatically refunded once HMRC updates your code.
See How Your Tax Code Affects Your Pay
A change in your tax code can significantly impact your monthly take-home pay. Use our calculator to model different scenarios and see exactly how much you'll take home.
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