Tax codes, 2026/27
K tax codes
A K code means you have income or deductions higher than your Personal Allowance, so your employer adds extra taxable pay instead of giving you tax-free pay.
A K code adds the number × £10 to your taxable pay
Tax codes with a K mean you have income or deductions that are higher than your tax-free Personal Allowance and are not already taxed. Instead of tax-free pay, your employer adds the number × £10 to your taxable pay. GOV.UK's employer example: with K475, £4,750 is added, so a £27,000 salary is taxed as £31,750. With the 2026/27 rates that is £6,350.00 of income tax a year, £529.17 a month.
| Code | Added to taxable pay a year | Tax on £30,000 a year | Tax on £30,000 with 1257L |
|---|---|---|---|
| K100 | £1,000 | £6,200.00 | £3,486.00 |
| K475 | £4,750 | £6,950.00 | £3,486.00 |
| K1000 | £10,000 | £8,460.00 | £3,486.00 |
Why you might have a K code
- You're paying tax you owe from a previous year through your wages or pension.
- You get the State Pension or taxable state benefits.
- You get company benefits you pay tax on, such as a company car.
- Interest on your savings is more than your Personal Savings Allowance.
Your employer cannot take more than half your pay
Employers and pension providers cannot take more than half of your pre-tax wages or pension when using a K code.
How to check or fix your tax code
- Find your code on your payslip, in a tax code letter from HMRC, or by signing in to HMRC's Check your Income Tax service or the HMRC app.
- If it looks wrong, use the same online service to check your jobs, pensions, estimated income and company benefits, and update anything that is wrong or missing. GOV.UK says this is the quickest way.
- If you have just started a new job, GOV.UK says to wait 35 days for HMRC to get your new income details before contacting them. If you left a job without a P45, ask your old employer for one.
- HMRC will tell you and your employer the new code within 15 working days. If you paid too much tax, your employer usually refunds it through your pay once the new code is used.
- If you cannot use the online service, contact HMRC about Income Tax.
Only HMRC can set or change your tax code. This page explains what codes mean; it is not personal tax advice. Sources: GOV.UK: If you think your tax code is wrong; GOV.UK: If you've paid too much or too little tax; GOV.UK: Tax codes.
Questions about K codes
What does K mean in a tax code?
It means you have income or deductions which are higher than your tax-free Personal Allowance and are not already being taxed, so extra taxable pay is added instead of tax-free pay.
How is a K code worked out?
Multiply the number in the code by 10 and add it to your taxable pay. K475 adds £4,750, so £27,000 of pay is taxed as £31,750.
Is there a limit on tax with a K code?
Yes. Employers and pension providers cannot take more than half of your pre-tax wages or pension when using a K tax code.
Other tax codes
- 1257LThe standard code: £12,570 tax-free.
- BRAll pay from this job taxed at 20%.
- D0All pay taxed at 40% (SD0: 21%).
- D1All pay taxed at 45% (SD1: 42%).
- 0TNo tax-free allowance on this job.
- NTNo tax taken from this income.
- Emergency codesW1, M1 and X: each payday on its own.
- Tax code checkerType your code to see what it means.
This page explains what K codes mean under GOV.UK and HMRC guidance for 2026/27. It is general information, not personal tax advice. Only HMRC can confirm or change your tax code. Tax figures are estimates for a full tax year at steady pay.
Sources
Rules checked 21 October 2026 against: GOV.UK: If you have a K in your tax code; GOV.UK: What your tax code means; GOV.UK: Understanding your employees' tax codes; HMRC PAYE Manual PAYE11095: K codes; HMRC: Rates and thresholds for employers 2026 to 2027. How we calculate.
Tax rates and thresholds are taken from HMRC, GOV.UK and Scottish Government publications. Contains public sector information licensed under the Open Government Licence v3.0.