What does my tax code mean?

A UK tax code tells your employer how much income tax to deduct from your pay each period. The number in a standard code (e.g. 1257 in 1257L) multiplied by 10 gives your tax-free personal allowance. The letter describes your situation. L is the most common, meaning you get the standard personal allowance. BR, D0, D1, and K codes have different meanings described in the calculator above.

What is 1257L and why do most people have it?

1257L is the standard tax code for 2026/27. The 1257 means a personal allowance of £12,570 (1257 × 10) and the L means you are entitled to the standard allowance. It applies to the majority of UK employees with one job and no other adjustments to their allowance.

What does W1 or M1 mean on my tax code?

W1 (week 1) or M1 (month 1) means your employer is deducting tax on a non-cumulative basis, meaning each pay period is taxed in isolation rather than cumulatively across the year. This is known as an emergency tax code and is commonly applied at the start of a new job before HMRC updates your record. It can result in over- or under-payment of tax during the year, which HMRC corrects through your tax return or an automatic adjustment.

A K code (e.g. K500) means your deductions, such as a company car benefit, private medical insurance, or unpaid tax from a previous year, exceed your personal allowance. The K number multiplied by 10 is the amount added to your income before tax is calculated. Your employer cannot deduct more than 50% of your gross pay in any single period because of this code.

How do I check if my tax code is correct?

HMRC sends a tax code notice (form P2) when your code changes. You can also check and update your tax code online through your Personal Tax Account at gov.uk. If you think your code is wrong, for example if you are on an emergency code but have been employed for a while, contact HMRC via phone or online to request a correction.

What does the S prefix mean (e.g. S1257L)?

The S prefix means Scottish income tax rates apply to your non-savings, non-dividend income. Scotland has its own income tax bands set by the Scottish Parliament, ranging from 19% (Starter rate) to 48% (Top rate) in 2026/27. If you live in Scotland your employer should use an S-prefixed code. National Insurance rates are the same throughout the UK.

Tax & Income

Tax Code Calculator & Checker

Enter any UK tax code to get a plain-English explanation, your effective personal allowance, and an estimated tax comparison.

Updated April 2026

Your details

Tax code

Found on your payslip or P60. Examples: 1257L, BR, D0, K500, S1257L, 1257L W1

Annual salary (for tax estimate)

Common codes

Your results

What Tax Code 1257L Means

Tax code

1257L

Standard personal allowance (£12,570/year), as expected for most employees

Your allowance: £12,570/year
Standard allowance (1257L): £12,570/year

Breakdown

What this code means

Tax code 1257L gives you a personal allowance of £12,570 per year. The L suffix means you are entitled to the standard personal allowance.

✓Tax-free allowance: £12,570/year (£1,048/month).
✓The L suffix means you are entitled to the standard personal allowance.
✓This matches the standard personal allowance, as is typical for most UK employees.

Monthly tax-free amount: £1,048/month

Estimated income tax

On a salary of £35,000 · 2026/27 England/Wales rates · income tax only

Estimated annual tax (1257L): £4,486
Standard code (1257L) annual tax: £4,486
Difference vs standard: Same

Related calculators

Income Tax Calculator Salary Calculator National Insurance

Frequently asked questions

How UK tax codes work

Your tax code tells your employer how much income to treat as tax-free each pay period. For a standard code like 1257L, the number (1257) multiplied by 10 gives your annual personal allowance (£12,570). The letter tells your employer about your circumstances, L is the most common and simply confirms you get the standard allowance.

When a tax code goes wrong

Emergency codes (W1/M1), D0, or 0T codes can cause you to overpay tax during the year. HMRC's cumulative PAYE system usually corrects overpayments automatically at year end, but you can also claim a refund through your Personal Tax Account or by calling HMRC. If you have been on an emergency code for more than a couple of pay periods, it is worth contacting HMRC directly to resolve it, particularly if you have provided your P45 to your employer.

How to update your tax code

You can check and update your tax code online through your HMRC Personal Tax Account (gov.uk). Changes you make online are usually reflected in your next payslip. For complex situations, K codes, multiple income sources, or high-income adjustments, it is worth speaking to HMRC directly or consulting a tax professional.

Sources & methodology

Built and maintained by Tim, a personal finance enthusiast (not a financial adviser). Last reviewed April 2026. Rates and thresholds come from official UK government publications.

HMRC: Income Tax rates and allowances · Official rates, bands and thresholds
GOV.UK: National Insurance rates · Employee and employer NI rates
Scottish Government: Income Tax · Scottish income tax rates and bands

Figures are estimates only. This is not financial or tax advice. For help with your specific situation, speak to HMRC or a qualified adviser.