Tax Code Checker UK

Enter your tax code and we will explain exactly what it means, how much personal allowance you have, and whether you should check with HMRC.

Your UK tax code tells your employer how much income tax to deduct from your pay each month. The standard code for 2025/26 is 1257L, which means you receive the full £12,570 personal allowance before any tax is charged. Any deviation from this code indicates an adjustment — and understanding why is essential to ensuring you pay the correct amount.

Tax codes ending in letters carry specific meanings. L indicates you are entitled to the standard personal allowance. BR means all income from that employment is taxed at the basic rate (common for second jobs). K codes indicate your deductions exceed your allowance, typically due to benefits in kind. Emergency codes such as 1257L W1 or 1257L M1 mean HMRC does not yet have your full details and is taxing each pay period in isolation.

HMRC estimates that around 1 in 3 PAYE taxpayers have been on an incorrect tax code at some point (HMRC Annual Report, 2023). Overpayments can be reclaimed for up to four years. Enter your code below to see exactly what it means and whether action is required.

How to check your tax code

  1. Find your tax code on your payslip, P45, or HMRC tax code notice
  2. Enter it into the checker above
  3. See what the code means, your personal allowance, and tax band
  4. Follow our guidance if the code appears incorrect

Written by the CalcStack team · Last updated March 2026

Find your tax code on your payslip or P60

Frequently asked questions

What does my tax code mean?▾
Your tax code tells your employer how much tax-free income you are entitled to. The number multiplied by 10 gives your personal allowance. The letter(s) indicate your situation — for example, L means the standard allowance, M means you receive Marriage Allowance.
What is the most common tax code?▾
The most common tax code for 2025/26 is 1257L. This means you have the standard Personal Allowance of £12,570. You do not pay tax on the first £12,570 of your income.
What is an emergency tax code?▾
An emergency tax code (ending in W1, M1, or X) means HMRC has not yet confirmed your correct code. Your employer taxes each pay period independently rather than cumulatively. This can result in paying too much or too little tax.
What does a K tax code mean?▾
A K code means your tax-free allowance has been reduced to below zero, usually because of taxable benefits like a company car. HMRC adds the value of untaxed benefits to your income before calculating tax.
Why has my tax code changed?▾
Tax codes can change when: your personal allowance changes, you start or stop receiving taxable benefits, you have underpaid or overpaid tax, you start or stop Marriage Allowance, or your employment circumstances change.
How do I check if my tax code is correct?▾
Check your tax code through your Personal Tax Account on gov.uk, or call HMRC. Compare the personal allowance in your tax code with the standard £12,570 and consider any adjustments for benefits, underpayments, or Marriage Allowance.
What does the S prefix mean in a Scottish tax code?▾
The S prefix (e.g., S1257L) means you pay income tax at the Scottish rates, which are set by the Scottish Parliament. Your personal allowance remains the same, but the tax bands and rates differ from the rest of the UK.
What does BR mean as a tax code?▾
BR means all your income from this employment is taxed at the basic rate (20%) with no personal allowance applied. This is common for second jobs where your personal allowance is already used by your first employer.
Can I have different tax codes for different jobs?▾
Yes. If you have more than one job, your personal allowance is usually applied to your main job (with an L code), and your second job is given a BR or D0 code. You should not have the personal allowance applied twice.
How do I change my tax code?▾
Contact HMRC by phone or through your Personal Tax Account on gov.uk. You can also write to them. If your employer is using the wrong code, HMRC will issue a new code directly to your employer.

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© 2026 CalcStack — a Flavoureak UK Ltd product. Tax codes are based on 2025/26 HMRC guidance. This tool provides general information only and is not financial or legal advice.