UK Tax Code Calculator 2026/27
Decode and verify your official HMRC UK tax code for the 2026/27 tax year. Find out your exact tax-free allowance, understand prefixes and suffixes (S, C, K, L, M, N, BR, 0T), and see how your code affects your take-home pay.
Tax Code Decoder
HMRC 2026/27 PAYE Tax Code Specifications
Calculation Breakdown
Cumulative Standard HMRC Basis
£1,047.50/mo • £241.73/wk
On £50,000 annual gross salary
Standard baseline single worker
Benefiting from additional allowance
•Code Meaning: Standard UK Personal Allowance: £12,570 tax-free earnings.
•Rest of UK (England & NI): Standard HMRC income tax schedules apply.
•Your tax matches the standard UK personal allowance exactly.
How Your Tax Code Was Decoded (1257L)
Standard UK Personal Allowance: £12,570 tax-free earnings.
Anatomy & Prefix Analysis
Standard (rUK)Code: 1257L • Jurisdiction: England & NI • Status: Standard Cumulative
The prefix letter determines which nation’s tax brackets apply to your employment wages.
Numerical Allowance Multiplier
£12,570.00Annual Tax-Free Allowance: £12,570.00
Monthly Allowance: £1,047.50 / month
Weekly Allowance: £241.73 / week
In standard codes, the numbers are multiplied by 10 to establish your total tax-free personal allowance.
Impact vs Benchmark 1257L Code
+£0.00 taxTax on 1257L: £7,486.00 | Tax on 1257L: £7,486.00 | Variance: £0.00 (Identical)
If this code is incorrect, report it immediately via the HMRC app or your Personal Tax Account to avoid underpaying or overpaying tax.
£7,486.00
How this calculator works
How it works
- 01Parses the entered UK tax code into regional jurisdiction prefixes (S for Scottish rates, C for Welsh rates), numeric allowance multipliers, and HMRC status suffixes.
- 02Decodes numeric portions into annual, monthly, and weekly tax-free allowances (e.g. 1257 becomes £12,570/year).
- 03Identifies flat-rate codes: BR (all income taxed at 20%), D0 (all taxed at 40%), D1 (all taxed at 45%), and NT (no tax deducted).
- 04Evaluates Marriage Allowance codes: M (received 10% transferred allowance +£1,260) and N (transferred 10% allowance to spouse -£1,260).
- 05Calculates negative allowance K-codes, where taxable company perks or unpaid previous year taxes exceed your personal allowance, adding notional income to each pay cycle.
- 06Simulates estimated income tax on your salary and compares the result to the standard 1257L benchmark code to highlight overpayments or underpayments.
Tax rules that apply
- •Standard Code 1257L: 1257 indicates £12,570 in tax-free Personal Allowance (£1,257 × 10). The letter L denotes entitlement to the standard statutory allowance without special adjustments.
- •Marriage Allowance Letters (M & N): Suffix M means you received 10% (£1,260) of your spouse's allowance, giving you £13,830 tax-free. Suffix N means you transferred £1,260 of allowance to your spouse, giving you £11,310 tax-free.
- •K-Codes (Negative Allowance): Codes starting with K (e.g. K450) indicate company benefits or state pension exceed your personal allowance. The number multiplied by 10 (£4,500) is added to your pay as extra taxable income, subject to HMRC's 50% pay cap.
- •Flat-Rate Codes (BR, D0, D1): Codes without numbers tax all pay at a fixed rate: BR at 20% basic rate, D0 at 40% higher rate, and D1 at 45% additional rate. Code NT means zero income tax is deducted.
- •Regional Prefixes (S & C): Prefix S applies Scottish Government income tax bands (19% to 48%). Prefix C applies Welsh Rates of Income Tax.
Current Tax Rates
| Tax / Deduction | Rate | Notes |
|---|---|---|
| 1257L (Standard) | £12,570 / year tax-free | Standard UK Personal Allowance |
| M Suffix (Marriage In) | £13,830 / year tax-free | +£1,260 transferred from spouse |
| N Suffix (Marriage Out) | £11,310 / year tax-free | -£1,260 transferred to spouse |
| Code BR | Flat 20% on all earnings | Common for second jobs/pensions |
| Code D0 | Flat 40% on all earnings | Higher rate second job code |
| Code D1 | Flat 45% on all earnings | Top rate second job code |
| Code 0T | £0 personal allowance | Emergency or allowance exhausted |
| K-Codes | Negative allowance added | Deductions capped at 50% of pay |
| Prefix S & C | Scottish (S) & Welsh (C) | Regional tax band variations |
What this calculator assumes
- Tax code decoding follows statutory HMRC PAYE rules for the 2026/27 tax year.
- Assumes benchmark comparison is made against the standard UK 1257L code for a single individual.
- Weekly and monthly allowances assume exact statutory 52-week and 12-month rounding.
Where our numbers come from
These calculators are based on official government tax rates and rules. We link directly to the source so you can verify everything yourself.
HMRC — Employer Tax Rates & Thresholds 2025–2026
HM Revenue & Customs, United Kingdom
GOV.UK / HMRC — Understanding PAYE Tax Codes (1257L, BR, K-codes)
HM Revenue & Customs (HMRC), United Kingdom
HMRC — Income Tax & National Insurance Rates 2026/27
HM Revenue & Customs (HMRC)
Frequently Asked Questions
What does the standard 1257L tax code mean for 2026/27?
The standard tax code 1257L gives you £12,570 of tax-free Personal Allowance for the tax year (£1,047.50 per month or £241.73 per week). The letter L means you are an employee entitled to the standard statutory allowance without special marriage deductions or age-related additions.
What does a 'K' tax code mean and why is tax being added to my pay?
A K code (such as K450) means you have taxable perks or untaxed income that exceed your £12,570 Personal Allowance. The number multiplied by 10 (e.g. £4,500) is added to your wage packet as additional taxable income each pay cycle. HMRC enforces a statutory rule that tax deducted under a K code cannot exceed 50% of your gross wages in any pay period.
What do the BR, D0, and D1 tax codes mean?
These are flat-rate codes with zero tax-free allowance. BR taxes all earnings from that job at the basic rate (20%). D0 taxes all earnings at the higher rate (40%), and D1 taxes all earnings at the additional rate (45%). These are common for second jobs, side gigs, or occupational pensions where your primary job already utilizes your full £12,570 allowance.
What do the letters S and C mean at the start of a tax code?
The letter S indicates that you are a Scottish tax resident, meaning your employment income is subject to Scottish Government tax bands (19% starter up to 48% top rate). The letter C denotes a Welsh tax resident subject to Welsh Rates of Income Tax (WRIT).
Why has HMRC put me on an emergency tax code (0T, 1257L W1/M1)?
You are typically put on an emergency tax code when starting a new job if your employer has not received your P45 from your previous employer, or if HMRC does not have enough information about your total earnings. A 1257L W1 or M1 code gives you 1/12th or 1/52nd of the personal allowance without cumulative carryovers. A 0T code gives you £0 personal allowance.
How do I query or change an incorrect tax code with HMRC?
If you believe your tax code is incorrect (for example, you are paying tax on a company car you no longer drive or you are on an emergency code), you can check and update your details using the free HMRC app, through your online Personal Tax Account on GOV.UK, or by calling HMRC on 0300 200 3300.
