What Is a Tax Code? Every Code Explained (2025-26)
The combination of numbers and letters on your payslip tells HMRC and your employer exactly how much tax-free income to give you. Here is what every element means — and what to do when it looks wrong.
How to Read Your Tax Code
A standard tax code consists of a number followed by a letter — for example, 1257L. The number tells you the size of your tax-free income, and the letter tells you why. The rule for the number is simple: multiply it by 10 to get your annual personal allowance.
- Code 1257 → £12,570 annual allowance (the standard Personal Allowance for 2025-26)
- Code 800 → £8,000 allowance (reduced, perhaps due to a taxable benefit in kind)
- Code 1357 → £13,570 allowance (enhanced, perhaps due to job expenses or Marriage Allowance received)
Your employer or pension provider divides this annual allowance by the number of pay periods in the year — 52 for weekly pay, 12 for monthly — and applies it to each payment. This is why your tax code does not change your total annual tax bill, only its timing across pay periods.
What the Letters Mean
| Letter | Meaning |
|---|---|
| L | Standard Personal Allowance (most common) |
| M | Marriage Allowance — you have received 10% of your partner's allowance |
| N | Marriage Allowance — you have transferred 10% of your allowance to your partner |
| T | Your tax code includes other items HMRC needs to review (e.g. complex calculation) |
| S | Scottish rate — your income tax uses Scottish rates (prefix S, e.g. S1257L) |
| C | Welsh rate — your income tax uses Welsh rates (prefix C, e.g. C1257L) |
| BR | Basic Rate — all income taxed at 20%, no personal allowance used here |
| D0 | Higher Rate — all income taxed at 40%, no personal allowance |
| D1 | Additional Rate — all income taxed at 45% |
| NT | No Tax — no tax deducted at all (rare, used for certain arrangements) |
| K | Negative allowance — your untaxed income or benefits exceed your allowance |
| 0T | Zero allowance — no allowance at all (all income taxed immediately) |
| W1 or M1 | Emergency basis — tax calculated per week (W1) or per month (M1) with no cumulative adjustment |
The Standard Code: 1257L in Detail
The 1257L code is correct for the vast majority of UK employees and pensioners in 2025-26. It corresponds precisely to the standard Personal Allowance of £12,570. HMRC sends this code automatically to your employer when you start a new job, assuming you have no additional complications — no company car, no underpaid tax from prior years, no taxable benefits.
If your code is 1257L and your circumstances are straightforward (one job, no benefits, no prior-year debts), then you are being taxed correctly. You do not need to take any action.
Scottish and Welsh Codes
Scottish taxpayers (defined by HMRC based on where you live, not where you work) receive a code prefixed with S — for example, S1257L. This tells your employer to apply the Scottish income tax rates, which differ from the rest of the UK: Scotland has six bands, including a 42% Higher Rate threshold of approximately £43,663 and a 45% Advanced Rate (versus England's 40% and 45%). Welsh taxpayers receive codes prefixed with C (for Cymru), though Welsh rates are currently identical to England's.
Emergency Tax Codes: W1 and M1
When HMRC does not have enough information about your income — for example when you start a new job without a P45 — your employer may apply an emergency tax code. This is typically your standard allowance (1257L) but with a W1 or M1 suffix, meaning the tax is calculated on a "non-cumulative" basis.
Normally, PAYE is calculated cumulatively: if you were overpaid tax in April, it corrects itself in May. Under W1/M1 emergency coding, each pay period is calculated independently as if it were the first of the year. This does not guarantee you overpay, but it does mean the system cannot correct prior overpayments automatically, and you may need to claim a refund.
Emergency coding is temporary. Once HMRC receives the necessary information (usually via an RTI submission from your employer or you submitting a P60 from your old job), the code updates and future deductions correct for any over or underpayment.
BR, D0 and D1: Second Income Codes
These codes appear on a second job or second pension source where your Personal Allowance is already allocated elsewhere. BR (Basic Rate at 20%) is the most common — it applies when a second employer has no information about your allowance. D0 (Higher Rate at 40%) is used when HMRC knows your first income already fills the basic rate band. D1 (45%) is rare and applies to additional rate taxpayers with multiple income streams.
If you receive a BR code on what you believe is your only or main income source, contact HMRC immediately — you may be overpaying tax significantly.
The K Code: When Benefits Exceed Your Allowance
A K code means you have a negative effective allowance — your employer adds income to your pay for tax purposes rather than subtracting an allowance. This sounds alarming but is simply HMRC's mechanism for collecting tax on benefits or underpayments that exceed your standard allowance.
Example: a £50,000 salary earner has a company car worth £8,000 in benefit-in-kind. This is added to their income before the allowance is applied. If the benefit (£8,000) exceeds the allowance remaining after other adjustments, HMRC may issue a K code. Your employer cannot deduct more than 50% of your gross pay in a single period under a K code — a built-in protection against extreme over-deduction.
How to Check and Fix Your Code
Your tax code appears on every payslip, on your P60 at year end, and on the PAYE correspondence (P2 notice) that HMRC sends you — usually in April when codes are updated. You can also check and manage your code in your HMRC Personal Tax Account at gov.uk/personal-tax-account.
If your code looks wrong — the number is lower than expected, you have an unexplained letter, or you have a BR code on your main income — contact HMRC. Use the online check-and-change tool first; telephone enquiries go to 0300 200 3300. Changes take effect from the next payroll run. Any tax overpaid in the current year is usually refunded automatically via PAYE; overpayments from prior years require a formal repayment claim.
Frequently Asked Questions
What does 1257L mean on my tax code?
1257L is the standard tax code for 2025-26. The number 1257 × 10 = £12,570, your Personal Allowance. The letter L means you are on the standard allowance. Most employed UK workers will see this code on their payslip.
What does a BR tax code mean?
BR means all income from that source is taxed at 20% with no personal allowance applied. It is typically correct for a second job, but if it appears on your primary income source it is likely an error causing overpayment — contact HMRC to correct it.
How do I check my tax code and what to do if it is wrong?
Check via your HMRC Personal Tax Account, your payslip, or your P60. If it seems wrong, contact HMRC online or by phone (0300 200 3300). They will issue a corrected coding notice to your employer and refund any overpaid tax through PAYE.