Tax Code Calculator UK
Check your HMRC PAYE tax code, calculate your exact tax-free Personal Allowance, and see precisely how much Income Tax and take-home pay you will receive. Accurately decode 1257L, BR, K codes, Scottish prefixes, and emergency tax codes.
1257L is the standard UK tax code for 2026/27. It gives you a tax-free Personal Allowance of £12,570 per year.
| Breakdown | Year | Month | Week |
|---|---|---|---|
| Gross Income | £35,000.00 | £2,916.67 | £673.08 |
| Tax-Free Allowance | £12,570.00 | £1,047.50 | £241.73 |
| Taxable Income | £22,430.00 | £1,869.17 | £431.35 |
| Income Tax | £4,486.00 | £373.83 | £86.27 |
| National Insurance | £1,794.40 | £149.53 | £34.51 |
| Pension (5%) | £1,121.50 | £93.46 | £21.57 |
| Take-Home Pay | £28,589.60 | £2,382.47 | £549.80 |
Calculations based on HMRC 2026/27 PAYE Income Tax thresholds and Class 1 National Insurance statutory rates. Personal allowances and K code additions are annualized for full financial year modeling.
How This UK Tax Code Calculator Works for 2026/27
Your UK PAYE tax code tells your employer or pension provider how much Income Tax to deduct from your wages before you receive your net pay. Using an accurate tax code calculator or tax code checker is essential to ensure you are not overpaying HMRC or facing an unexpected tax bill at the end of the financial year.
Our comprehensive tax code calculator uk decodes any HMRC PAYE tax code—including standard allowances (1257L), flat-rate secondary employment codes (BR, D0, D1), negative personal allowances (K tax code calculator), marriage allowance adjustments (M, N), and Scottish or Welsh prefixes (S, C). By combining your tax code with your gross earnings, you can model your exact tax deductions alongside our UK income tax calculator, National Insurance calculator, and comprehensive PAYE calculator.
Complete Guide to UK Tax Code Letters and Meanings
A UK tax code is normally made up of numbers and letters. The numbers indicate your annual tax-free Personal Allowance divided by 10. For instance, the number 1257 multiplied by 10 gives an annual allowance of £12,570. The letter tells HMRC and your employer’s payroll software how that allowance should be treated.
| Tax Code / Letter | What It Means | 2026/27 Tax Allowance | Typical Scenario |
|---|---|---|---|
| 1257L | Standard Personal Allowance | £12,570 tax-free | Most UK employees with a single job or pension. |
| BR | Basic Rate (flat 20%) | £0 allowance | Second jobs or pensions where main job uses the allowance. |
| 0T | Zero Personal Allowance (tiered rates) | £0 allowance | New starter without P45, or income exceeding £125,140. |
| K Codes (e.g. K450) | Negative Personal Allowance | Untaxed benefits added to pay | Company car, medical benefits, or state pension exceeding allowance. |
| 1383M | Marriage Allowance Recipient | £13,830 (£12,570 + £1,260) | Partner transferred 10% of their unused allowance to you. |
| 1131N | Marriage Allowance Transferor | £11,310 (£12,570 – £1,260) | You elected to transfer 10% of your allowance to your spouse. |
| D0 | Higher Rate (flat 40% / Scottish 42%) | £0 allowance | Second employment where primary income already exceeds £50,270. |
| D1 | Additional Rate (flat 45% / Scottish 48%) | £0 allowance | Second income where primary salary exceeds £125,140. |
| NT | No Tax Deducted | All earnings free of Income Tax | Specific foreign earnings, bankruptcies, or statutory exemptions. |
| T | Review Code | Variable (e.g. 500T = £5,000) | HMRC requires manual annual review of personal tax affairs. |
| W1 / M1 / X | Emergency Non-Cumulative Basis | Standard monthly/weekly slice | Temporary code applied to each pay packet in isolation. |
| S Prefix (e.g. S1257L) | Scottish Income Tax Rates | £12,570 (Scottish tax bands) | Individuals whose main residence is located in Scotland. |
| C Prefix (e.g. C1257L) | Welsh Income Tax Rates | £12,570 (Welsh rates) | Individuals whose primary residence is in Wales. |
Understanding K Tax Codes: Negative Personal Allowances Explained
If your payslip displays a tax code starting with K (such as K450, K100, or K850), our K tax code calculator engine simulates the exact payroll calculation mandated by HMRC.
A K code is issued when your untaxed company benefits, state pension, or unpaid tax from a previous year exceed your Personal Allowance of £12,570. In payroll terms:
- Take the numbers after the letter K and multiply by 10 (e.g. K450 = £4,500).
- This figure is deemed negative allowance and is added directly to your gross salary to establish your taxable pay.
- For example, on a £40,000 gross salary with code K450, your taxable pay becomes £44,500. Income Tax is then calculated starting directly at the 20% basic rate band with zero tax-free allowance.
- The 50% Regulatory Cap: Under UK statutory PAYE regulations, an employer cannot deduct more than 50% of your total gross pay in any single pay period under a K code. This protects employees from having their entire paycheck consumed by tax deductions.
What is the BR Tax Code and Why Has HMRC Assigned It?
The BR tax code stands for “Basic Rate”. If you need a BR tax code calculator, our tool demonstrates the exact financial impact of having this code applied to your income.
Under a BR code, you receive zero personal allowance (£0), and every single penny earned is taxed at a flat 20% basic rate. HMRC typically issues a BR code in two common circumstances:
- Second Jobs or Multiple Employments: HMRC assigns your entire £12,570 Personal Allowance to your primary job (coded 1257L). Your second job is assigned BR to avoid double-claiming the tax-free allowance.
- Occupational or Private Pensions: If you receive an annuity or company pension while continuing to work, the pension often carries a BR code if your salary already absorbs your personal allowance.
If BR has been assigned to your sole, primary job in error, you will be overpaying Income Tax by £2,514 per year (£209.50 per month). You should immediately contact HMRC or update your employment details via your Personal Tax Account to revert your primary job to 1257L.
Emergency Tax Codes: W1, M1, and X Explained
An emergency tax code usually shows as 1257L W1 (Week 1), 1257L M1 (Month 1), or 1257L X.
Emergency codes are typically applied if you start a new role without a P45 from your previous employer, or before HMRC transmits your official coding notice to your payroll department. Once your new employer receives your tax history, your code switches back to cumulative and any overpaid tax is automatically refunded in your next pay packet.
Scottish (S) and Welsh (C) Tax Code Variations
Income Tax rates on non-savings, non-dividend income are devolved in Scotland and Wales:
- Scottish Tax Codes (S prefix, e.g. S1257L, SBR, SD0): Scotland operates six income tax bands for 2026/27 (Starter 19%, Basic 20%, Intermediate 21%, Higher 42%, Advanced 45%, and Top 48%). Anyone whose primary residence is in Scotland must be on an S code.
- Welsh Tax Codes (C prefix, e.g. C1257L): The Welsh Government sets Welsh Rates of Income Tax (WRIT). For 2026/27, Welsh rates remain aligned with England and Northern Ireland (20%, 40%, 45%).
Comparing 1257L, BR, and K450 on a £40,000 Salary
To illustrate how significantly your PAYE tax code changes your payslip, let us examine an employee earning a £40,000 annual salary under three different tax codes:
| Payslip Metric | Standard 1257L | Basic Rate (BR) | Negative Code (K450) |
|---|---|---|---|
| Gross Annual Pay | £40,000.00 | £40,000.00 | £40,000.00 |
| Personal Allowance Adjustment | £12,570 tax-free | £0 allowance | +£4,500 added to taxable pay |
| Taxable Income for PAYE | £27,430.00 | £40,000.00 | £44,500.00 |
| Annual Income Tax | £5,486.00 | £8,000.00 | £8,900.00 |
| Class 1 National Insurance | £2,194.40 | £2,194.40 | £2,194.40 |
| Annual Net Take-Home | £32,319.60 | £29,805.60 | £28,905.60 |
| Monthly Take-Home Pay | £2,693.30 | £2,483.80 | £2,408.80 |
Notice that Class 1 National Insurance remains identical across all three examples (£2,194.40). National Insurance is governed by statutory primary thresholds and is completely unaffected by your Income Tax code. To learn more about NI bands, use our National Insurance calculator.
How Tax Codes Interact with Your Entire UK Paycheck
Your tax code is only one component of your monthly payslip. To get an exact picture of your disposable income, explore our interconnected suite of UK payroll tools:
- Take Home Pay Calculator UK: Our homepage flagship calculator for quick salary-to-net calculations.
- UK Salary Calculator: Model total compensation packages with company pensions and student loan plans.
- Net Salary Calculator: Calculate hourly, daily, weekly, and monthly net wage comparisons.
- Income Tax Calculator UK: Full breakdown of basic (20%), higher (40%), and additional (45%) rate tax bands.
- PAYE Calculator UK: Dedicated HMRC payroll engine modeling monthly cumulative PAYE deductions.
- National Insurance Calculator: Class 1 employee and employer NI contributions for 2026/27.
What to Do If Your Tax Code Is Wrong
If your tax code looks incorrect, you should not wait until the end of the tax year. Overpaying means giving HMRC an interest-free loan; underpaying means facing an unexpected tax demand via a P800 tax calculation notice.
- Sign in to your HMRC Personal Tax Account: Use GOV.UK or the official HMRC mobile app. Check the “Pay As You Earn (PAYE)” section to see why HMRC generated your specific code.
- Review Your Company Benefits: If you no longer have a company car, private healthcare, or other taxable perks, update the estimated benefit value directly on your account.
- Check Multiple Employments: Ensure your main job is allocated your 1257L allowance and any second jobs are designated BR or D0 appropriately.
- Claiming a Tax Refund: When HMRC updates your tax code, they issue a revised Coding Notice (P2) to your employer electronically. On your next regular payday, your payroll department will automatically refund any overpaid tax directly into your bank account.
Frequently Asked Questions About UK Tax Codes
The standard UK tax code for most employees in the 2026/27 tax year is 1257L (or S1257L in Scotland and C1257L in Wales). It gives you the standard annual tax-free Personal Allowance of £12,570. This equates to £1,047.50 of tax-free income per month, or £241.73 per week.
BR stands for Basic Rate. It means you receive £0 of tax-free Personal Allowance on that specific employment or pension, and all earnings are taxed at a flat 20% basic rate. BR is commonly issued for second jobs or pensions where your primary employment already utilizes your £12,570 allowance. If you earn less than £12,570 in total across all jobs, you can contact HMRC to split your personal allowance.
A K tax code applies when your untaxed taxable benefits (such as company cars, private health insurance, or state pension) exceed your tax-free Personal Allowance. Instead of receiving tax-free income, the numbers after the K (multiplied by 10) are added to your gross pay to form your taxable earnings. HMRC rules strictly limit the tax deducted under a K code to a maximum of 50% of your gross pay in any single pay period.
An emergency tax code ends with W1 (Week 1), M1 (Month 1), or X. It calculates your tax on a non-cumulative basis for each individual pay period without accounting for tax previously paid or unused allowance during the financial year. It is usually issued temporarily when starting a new job before your employer receives your P45. Once HMRC sends a cumulative code, any overpaid tax is automatically refunded on your next normal payslip.
No. Your tax code applies strictly to PAYE Income Tax. Class 1 National Insurance contributions are calculated independently using fixed statutory weekly and monthly thresholds (£12,570 Primary Threshold and £50,270 Upper Earnings Limit for 2026/27). Whether you are on code 1257L, BR, or K450, your National Insurance deductions remain completely identical.
The S prefix (e.g. S1257L) indicates you are a Scottish taxpayer subject to Holyrood’s six devolved income tax bands (Starter 19%, Basic 20%, Intermediate 21%, Higher 42%, Advanced 45%, and Top 48%). The C prefix (e.g. C1257L) indicates a Welsh taxpayer. For 2026/27, Welsh Rates of Income Tax remain aligned with England and Northern Ireland (20%, 40%, 45%).
These codes reflect the UK Marriage Allowance. If your spouse or civil partner earns less than the £12,570 Personal Allowance, they can transfer 10% (£1,260) of their allowance to you. The recipient receives code 1383M (giving £13,830 tax-free allowance, saving up to £252/yr in tax), while the transferring partner receives code 1131N (£11,310 allowance).
If you suspect your tax code is wrong, check your HMRC Personal Tax Account online or via the HMRC app. You can update your estimated annual income, report changes to company benefits, or allocate allowances across multiple jobs. HMRC will then issue a corrected PAYE Coding Notice (P2) directly to your employer’s payroll. Any tax overpaid in the current tax year will be refunded automatically in your next wage.
Methodology & Statutory UK Sources
All calculations performed by our PAYE tax code calculator are verified against HM Revenue & Customs (HMRC) specifications for the 2026/27 tax year. For official guidance and to update your coding notice online, consult the following authoritative resources: