What does 1257L mean?

1257L is the standard tax code for 2026/27. The number is your tax-free allowance divided by 10, so you can earn £12,570 a year before income tax, and L means you get the standard Personal Allowance. Scottish taxpayers have S1257L and Welsh taxpayers C1257L.

What does a K tax code mean?

A K code means your untaxed income or taxable benefits, such as a company car, State Pension or tax owed from an earlier year, are more than your allowance. Instead of tax-free pay, an amount is added to your taxable pay. On £40,000, K475 takes £10,363.60 a year compared with £5,486.00 on 1257L. Employers cannot take more than 50% of your pre-tax pay in a period under a K code.

What is an emergency tax code?

An emergency code ends in W1, M1 or X (or shows NONCUM on your payslip). Each pay period is taxed on its own, so you do not get the allowance for months before you started. Starting a £30,000 job in October on 1257L M1 takes £1,743.00 by April against £486.00 actually due. HMRC usually issues a normal code within 35 days of your start date.

Why is my tax code BR or 0T?

BR taxes all pay from a job at 20% and is normal on a second job. 0T gives no allowance, used when it is used up elsewhere or your employer lacks your details. On your only job both overcharge: BR on £20,000 takes £4,000.00 instead of £1,486.00, and 0T on £30,000 takes £6,000.00 instead of £3,486.00.

What do the letters M, N and T mean in a tax code?

M means you receive £1,260 of your partner's Personal Allowance through Marriage Allowance; N means you have transferred that amount to your partner. T means HMRC has made other calculations to work out your allowance.

How do I change a wrong tax code?

Check it in the HMRC app or your personal tax account at gov.uk, and update anything that is wrong, such as a job that has ended, a benefit you no longer get or estimated income. If you have started a new job, give your employer your P45 or complete their starter checklist. Overpaid tax comes back through payroll once the code is corrected, or as a refund.

Tax Code Calculator 2026/27

Name: UK Tax Code Calculator
Author: Alexandre Bernier

Find out what your tax code means, how much tax it takes over the year, and whether you are paying too much or too little.

Last updated: October 2026 · 2026/27 tax rates

Your code and pay

Tax code

As shown on your payslip, P60 or HMRC app, including any W1, M1 or X.

Annual salary from this job

Months of this tax year paid on this code

Matters for emergency codes. Assumes no other pay earlier in the tax year.

Where you live

Tax deducted under 1257L over the year

£3,486.00

This code collects the same tax as 1257L on this pay.

Allowance in this code

£12,570 a year

Tax due on 1257L

£3,486.00

On £30,000.00 of pay, taper applied

Paying more by

£0.00

About £290.50 a month deducted

What 1257L means

1257: Tax-free pay of £12,570 a year (the number times 10).
L: You get the standard tax-free Personal Allowance.

If this is your only job and you have no taxable benefits or other income, this code looks right.

How to fix a wrong tax code

Check the code and how HMRC worked it out in the HMRC app or with check your Income Tax for the current year.
Update anything wrong there: a job that has ended, a company car you have handed back, or income HMRC has estimated too high.
If you have just started a job, give your new employer your P45 or complete their starter checklist. HMRC usually updates an emergency code within 35 days of your start date.
Tax codes are set by HMRC, so changes go through HMRC rather than your employer. Overpaid tax normally comes back through payroll once the code is fixed, or as a refund after the year ends. See gov.uk/tax-codes.

How it works

A tax code tells your employer how much of your pay to treat as tax-free. In most codes the number is your tax-free allowance divided by 10, so 1257L means £12,570, the standard Personal Allowance for 2026/27. The letter says why, an S or C prefix sets Scottish or Welsh rates, and W1, M1 or X on the end marks an emergency code.

This calculator reads the code, works out the tax PAYE will deduct under it, and compares that with what you would owe on the same pay with the standard code, applying the £100,000 allowance taper. It assumes this job is your only income, so a K or BR code will always show as "paying more": the explanation tells you whether that is expected.

Worked example: K475 on £40,000. HMRC's pay adjustment tables turn K475 into £4,759 added to your pay for the year (the number times 10, plus 9). Taxable pay is £44,759: £37,700 at 20% is £7,540 and the remaining £7,059 at 40% is £2,823.60, so PAYE takes £10,363.60. On 1257L you would pay £5,486.00; the £4,877.60 difference is the tax on whatever the K code is collecting. Half of £40,000 is well above that, so the 50% limit on K-code deductions does not bite.

L: the standard tax-free Personal Allowance. M: you receive 10% of your partner's allowance through Marriage Allowance. N: you have given 10% of yours to your partner. T: HMRC has made other adjustments to your allowance.

0T: no allowance, because it is used up or your employer lacks your details. BR: all pay at the basic rate of 20%. D0: all at the higher rate of 40%. D1: all at the additional rate of 45%. NT: no tax taken. BR, D0 and D1 are usually for a second job or pension.

S prefix: Scottish rates. Scottish taxpayers can also have SBR (20%), SD0 (21%), SD1 (42%), SD2 (45%) and SD3 (48%). C prefix: Welsh rates, which are currently the same as in England and Northern Ireland.

K: your untaxed income or benefits are more than your allowances, so an amount is added to your pay instead of a tax-free amount being taken off. Employers cannot take more than half of your pre-tax pay in a period under a K code.

Income tax calculators

This calculator is part of a family. The main calculator covers the general case.

Main calculator: Income Tax Calculator

PAYE tax, National Insurance and take-home pay for any UK salary, including Scotland.

Scottish Income Tax Calculator

Tax in all six Scottish bands, take-home pay, and how much more or less you pay than the rest of the UK.

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Marriage Allowance Calculator

Transfer 10% of one spouse’s Personal Allowance to a basic-rate partner. Up to £252/year.

Reviewed by Alexandre Bernier, LLM (UK), CFP®

Educational tool: estimates only. Not individual financial, investment, tax or legal advice. Using it does not create an adviser-client relationship. Rules and figures change; check them against current HMRC and GOV.UK guidance and speak to a qualified professional. Editorial policy →

Sources

Every rate and threshold used by this calculator is taken from the official pages below. If a figure here disagrees with one of these, the official page is right, please tell us.