WageK Tax Code — What It Means
You have income that is not taxed another way - such as company benefits or the State Pension - worth more than your tax-free allowance, so the code adds to your taxable pay instead of giving an allowance.
How K changes your pay on a £30,000 salary
| Code | Income tax / year | Per month | Take-home / month* |
|---|---|---|---|
| Standard 1257L | £3,486 | £291 | £2,210 |
| K | A K code adds untaxed income to your taxable pay rather than giving an allowance, so the exact figure depends on the code number. It can never take more than half your pre-tax pay. | ||
*Take-home per month here reflects income tax only; National Insurance and any student loan or pension are separate.
Why you might have the K code
- You get taxable benefits, such as a company car or medical insurance, worth more than your Personal Allowance.
- You are repaying tax owed from an earlier year through your wages or pension.
- You receive the State Pension or other untaxed income that is greater than your allowance.
How to fix a wrong code
A K code cannot take more than half your pre-tax pay in any pay period. If the deductions look wrong, check the breakdown in your Personal Tax Account or contact HMRC.
Related codes: 1257L · NT · 0T · All tax codes
General information, not advice. Estimates assume the standard 1257L tax code and typical circumstances; your payslip may differ by a pound or two because HMRC payroll software truncates at each step. Verify with HMRC or an accountant for any decision. WageReckon stores no salary data - the calculators run in your browser.
Rates for the 2026-27 tax year, current as of 24 July 2026. Source: HMRC (gov.uk). Contains public sector information licensed under the Open Government Licence v3.0. Source: HMRC / gov.uk. See how we calculate.