The UK's most complete tax-code decoder
Decode any HMRC PAYE tax code in plain English. Add your salary, pension and student loan plan to see exact tax, National Insurance and take-home, broken down per pay period and visualised by tax band. Multi-year (2024/25, 2025/26 and 2026/27) and multi-region (England, Wales, Northern Ireland and Scotland).
A UK tax code is the short alphanumeric instruction HMRC gives your employer (or pension provider) so they know how much income tax to deduct from each pay packet. The code is built from a number, which represents your tax-free Personal Allowance divided by ten, and one or more letters that tell payroll which rates and rules to apply. Get the code wrong and you can lose hundreds of pounds a year through over-deduction, or build up an unexpected tax debt that HMRC will reclaim later through a code adjustment.
The standard code for most UK employees in 2026/27 is 1257L, which translates to a £12,570 Personal Allowance and the standard set of PAYE rules. Around 30 million PAYE taxpayers carry this code, but a sizeable minority sit on special codes such as BR (basic-rate-only on a second job), D0 (higher rate on every pound), 0T (no Personal Allowance pending P45), NT (no tax deducted at all) and the family of K-codes that add notional income from benefits-in-kind to your salary before tax is calculated.
Suffix letters describe entitlement: L for the standard allowance, M if you receive 10% of your spouse’s allowance under Marriage Allowance, N if you transferred yours, and T when HMRC needs to review the code. Prefixes describe region or special treatment: S for Scotland, C for Wales, and K when untaxed income exceeds your allowance. The trailing modifiers W1, M1 or X mark a non-cumulative or “emergency” basis where each pay period is taxed in isolation rather than against year-to-date totals. Emergency codes are normal for new starters but should resolve once HMRC issues a cumulative replacement.
Quick decode
1257L
Valid · England/Wales/NI rates · 2026/27
Personal Allowance of £12,570 per year. Standard Personal Allowance entitlement.
Personal Allowance: £12,570
| Letter | Type | Meaning |
|---|---|---|
| L | Suffix | Standard tax-free Personal Allowance |
| M | Suffix | Marriage Allowance recipient (10% transferred to you) |
| N | Suffix | Marriage Allowance transferor (you transferred 10%) |
| T | Suffix | HMRC needs to review your tax code |
| S | Prefix | Scottish Income Tax rates apply |
| C | Prefix | Welsh Income Tax rates apply |
| K | Prefix | Untaxed income exceeds your allowances |
| BR | Special | All income taxed at basic rate (20%) |
| D0 | Special | All income taxed at higher rate (40%) |
| D1 | Special | All income taxed at additional rate (45%) |
| NT | Special | No tax deducted |
| 0T | Special | No Personal Allowance: all income taxed through bands |
| W1 / M1 / X | Modifier | Emergency / non-cumulative basis |
Each code below has a dedicated 2026/27 page with worked examples, who it applies to and how to fix it if it’s wrong.
The number multiplied by 10 equals your tax-free Personal Allowance for the year. The letters tell your employer which rates and adjustments to apply.
1257L. It is used by approximately 85% of UK taxpayers and reflects the standard Personal Allowance of £12,570 with no adjustments.
W1, M1 or X means HMRC are taxing each pay period independently, usually because your employer has no P45. Most resolve within one or two payslips, but unresolved emergency codes are a common source of overpayment.
From April 2026 HMRC Dynamic Coding pushes new codes mid-year for triggers such as a new job, second job, company-car benefit added or removed, Marriage Allowance, and untaxed interest projections.
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