UK Tax Codes Explained 2026/27
What does your UK tax code actually mean? 14 explainers covering every common UK code: standard 1257L, basic-rate BR, higher-rate D0, additional D1, no-allowance 0T, K codes (owed tax), Marriage Allowance M/N, Scotland's S codes, Wales's C codes. Plain English with real examples.
1257L
1257L is the standard UK tax code for 2026/27. It means you're entitled to the full £12,570 personal allowance — the amount you can earn before paying…
BR Tax Code Explained (BR, BRX, Tax Code BR) UK 2026/27
BR stands for 'Basic Rate' — meaning all your income from this job is taxed at 20%, with no personal allowance applied. BR is most commonly used on se…
D0 — Higher Rate
D0 means all income from this source is taxed at the higher rate (40%) with no personal allowance applied. D0 is typically used on a second job or pen…
D1 — Additional Rate
D1 means all income from this source is taxed at the additional rate (45%) with no personal allowance applied. D1 is rare — typically used on a second…
0T Tax Code Explained (0T M1, 0T Non-Cumulative) UK 2026/27
0T means you have no personal allowance applied to this income — all earnings are taxed at the appropriate rate band (20%, 40%, or 45%) from the first…
NT — No Tax
NT stands for 'No Tax' — meaning no income tax is deducted from this income source. NT is rare and is typically applied when you're a non-UK resident,…
K Tax Code Explained (K123, K500) UK 2026/27 — Owed Tax
K codes (e.g. K123, K500) mean you have less than zero personal allowance — typically because of underpaid tax from previous years, taxable benefits-i…
M Tax Code Explained (1383M, 2026/27) — Marriage Allowance
M at the end of your tax code (e.g. 1383M for 2026/27) means you receive 10% of your spouse or civil partner's personal allowance — adding £1,260 to y…
N — Marriage Allowance Transfer
N at the end of your tax code (e.g. 1131N for 2026/27) means you've given 10% of your personal allowance to your spouse or civil partner. The number b…
T Tax Code Explained (T Code, T Code Tax) UK 2026/27
T at the end of your tax code (e.g. 1257T) means HMRC has used a non-standard calculation for your code that requires review — typically because of co…
W1 / M1 — Emergency / Week 1 / Month 1
W1 (Week 1) and M1 (Month 1) are emergency tax codes used when HMRC doesn't yet have enough information to calculate your full tax position. They tax …
S1257L — Scotland
S1257L is the Scottish equivalent of 1257L — the standard tax code for Scottish taxpayers in 2026/27. The S prefix indicates you're on Scottish income…
SBR — Scotland Basic Rate
SBR is the Scottish equivalent of BR — meaning all income from this source is taxed at the Scottish basic rate (20%) with no personal allowance. The S…
C1257L — Wales
C1257L is the Welsh equivalent of 1257L — the standard tax code for Welsh taxpayers in 2026/27. The C prefix indicates you're on Welsh income tax rate…
How to read a UK tax code
A typical UK tax code has three parts: a number (representing your tax-free allowance ÷ 10, e.g. 1257 = £12,570 allowance), a letter (specifying any modification — L for standard, M for Marriage Allowance recipient, etc.), and an optional prefix (S for Scotland, C for Wales). Some codes don't follow this format — BR, D0, NT, 0T are full codes by themselves and apply specific tax rates.
Pair this guide with our UK net pay calculator or the £15k–£200k take-home reference table to see exactly what your code means in net pay terms. For the recruiter overview that explains every code in one place, read UK Tax Codes Explained 2026. For tax-efficient ISA structuring, see UK ISA Allowance 2026/27. Wrong codes can cost you hundreds of pounds a year — most are correctable in one phone call to HMRC (0300 200 3300).
For payroll software / HR system import: download the full tax-codes dataset (JSON + CSV, CC BY 4.0).
UK tax code FAQs
What does the UK tax code 1257L mean in 2026/27? +
The standard tax code for 2026/27. The "1257" represents your Personal Allowance of £12,570 (the amount you can earn tax-free), and "L" means you're entitled to the basic Personal Allowance with no adjustments. It's applied cumulatively across the tax year. This is the default code for most UK PAYE employees with one job and no taxable benefits.
What does an emergency UK tax code (M1/W1) mean? +
M1 (Month 1) or W1 (Week 1) means HMRC is taxing you on a non-cumulative basis — each pay period taxed in isolation rather than year-to-date. This usually happens after a job change, when starting work mid-year, or when HMRC doesn't have your latest details. You're likely overpaying tax; HMRC will correct via P800 at year-end or you can call to update.
What does the UK tax code BR mean? +
BR = Basic Rate. All income on this code is taxed at 20% with no Personal Allowance applied. Usually applied to a second job or pension. If your total income is below the Personal Allowance, you're overpaying — call HMRC to allocate your allowance correctly across the income sources.
Why has my UK tax code changed? +
Common reasons: company benefits added (medical insurance, company car), unpaid tax from a previous year being collected, Marriage Allowance applied/removed, change in tax-free thresholds, or HMRC correcting a previous error. Check your latest P2 Coding Notice (HMRC posts/emails it) — it explains every adjustment to your code.
How do I challenge a wrong UK tax code? +
Contact HMRC via the Personal Tax Account online (gov.uk), the HMRC app, or phone (0300 200 3300). You'll need your NI number and recent payslip. Updates usually process within 1-2 weeks. If you've overpaid as a result, HMRC issues a refund via P800. Don't rely on your employer to fix it — only HMRC can change tax codes.
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