Quick reference: UK tax codes for 2025/26
UK tax codes use a number plus letter suffix (or letter prefix). Here's the full reference:
| Code | Meaning |
|---|---|
| 1257L | Standard £12,570 PA, no adjustments |
| 1383M | Received Marriage Allowance (PA + £1,260) |
| 1131N | Gave Marriage Allowance (PA − £1,260) |
| K500 | Negative allowance: £5,009 added to taxable income |
| BR | All income at 20%, no allowance (typically 2nd job) |
| D0 | All income at 40%, no allowance |
| D1 | All income at 45%, no allowance |
| NT | No tax (treaty / special) |
| 0T | No allowance, progressive bands |
| 1257L W1/M1/X | Emergency, non-cumulative |
| S prefix | Scottish income tax bands (e.g. S1257L) |
| C prefix | Welsh income tax bands (e.g. C1257L) |
Diagnosing tax code problems
Here are signs your tax code may be wrong and what to check:
- Tax code starts with K but you have no benefits — likely a prior-year underpayment being clawed back. Check Personal Tax Account.
- Both jobs on 1257L — only the main job should have it. Switch the second to BR/D0.
- Take-home doesn't match calculator by a lot — check W1/M1 (emergency) status.
- Code changed mid-year — HMRC issued a P2 tax code notice. Read the breakdown for justifications.
- Pension code lower than expected — State Pension may be reducing your allowance.
- Code includes "T" — there are temporary or special adjustments. Investigate via PTA.
To dispute or correct a code, log in to HMRC Personal Tax Account (gov.uk/personal-tax-account), call 0300 200 3300, or write. Most issues resolve within 4 weeks.
Three worked examples (UK 2025/26)
Example 1: Decoding 1257L on £35k
Standard code, no adjustments. PA £12,570. £35,000 − £12,570 = £22,430 taxable. Tax £4,486. NI £1,794.40. Take-home £28,720.
Example 2: Decoding K500 on £45k
K500 = -£5,009 allowance. Taxable: £45,000 + £5,009 = £50,009. Tax: £37,700 × 20% + £12,309 × 40%? Wait, basic rate band sits within £37,700 starting from £0. So basic £37,700 × 20% = £7,540, higher £12,309 × 40% = £4,924. Total tax £12,464. (Compare 1257L: £45,000 − £12,570 = £32,430 × 20% = £6,486 — much less. The K500 reflects ~£17,540 of taxable benefits behind the scenes.)
Example 3: Decoding BR on £6k second job
BR = 20% flat. £6,000 × 20% = £1,200 tax. NI may also apply if main job's NI threshold is unused (typically isn't — both employments may attract NI separately).
Common mistakes to avoid
- Multiplying the code number by 100 — it's × 10. So 1257 = £12,570, not £125,700.
- Treating BR / D0 / D1 as suffixes — they are full codes by themselves (no number).
- Believing the S prefix changes the allowance amount — it doesn't, only the bands.
- Confusing 0T with NT — 0T deducts tax progressively, NT deducts nothing.
- Not verifying tax codes annually — HMRC reissues them around early March each year (P2 notice).
- Assuming employer always uses the right code — payroll errors do happen; verify on payslip.
When to use this calculator
Use this checker when you receive your annual P2 notice (early March), when your tax code changes mid-year, when your take-home pay looks wrong, or before any salary negotiation. Verify against your Personal Tax Account at gov.uk for the authoritative breakdown.
Regional differences (Scotland, Wales, Northern Ireland)
Tax codes are issued by HMRC and apply to UK-wide employees. Scotland uses tax codes prefixed "S" (e.g. S1257L) to indicate Scottish income tax bands (Starter 19%, Basic 20%, Intermediate 21%, Higher 42%, Advanced 45%, Top 48%) — the numerical allowance portion is the same as rUK. Wales uses "C" (e.g. C1257L) for Welsh resident, but Welsh rates currently match UK. Northern Ireland uses standard UK codes throughout. The numerical part of the code (e.g. 1257 for £12,570 PA) is identical across the UK; only the prefix changes the band structure.