Tax Code K1000 Explained
K code — £10,000 is added to your taxable income, typical for employees with a combination of state pension plus a company car.
At a glance — K1000
- Personal Allowance
- −£10,000 (addition to taxable income)
- Region
- UK-wide (rUK / Wales)
- Cumulative?
- Yes
- Code type
- K code (addition)
What does K1000 mean?
You have income that is not being taxed another way and it is worth more than your tax-free allowance. The number is added to your taxable income rather than deducted.
Your taxable income is increased by £10,000 to account for untaxed benefits.
How much tax will you pay on K1000?
Annual income tax HMRC would deduct on 2025-26 rates for a range of salaries, assuming the full year on this code. National Insurance is additional and the same across the UK.
| Annual salary | England / Wales / NI — income tax | Effective rate | Take-home (pre-NI) |
|---|---|---|---|
| £20,000 | £6,000 | 30.0% | £14,000 |
| £30,000 | £8,460 | 28.2% | £21,540 |
| £50,000 | £16,460 | 32.9% | £33,540 |
| £80,000 | £28,460 | 35.6% | £51,540 |
| £100,000 | £36,460 | 36.5% | £63,540 |
For Scottish / rUK side-by-side, or to model your own salary, student loan and pension contributions, use the tax code checker.
Should you be on tax code K1000?
K codes are correct when HMRC needs to collect more tax than your Personal Allowance shelters — typically company car benefit, medical insurance, state pension or underpaid tax from a previous year. If the code looks high relative to your benefits in kind, request a P2 coding notice from HMRC and check the detail.
Related tax codes
K100 — K Code £1,000 Addition
K code — £1,000 is added to your taxable income because your untaxed benefits or arrears exceed your tax-free allowance.
K200 — K Code £2,000 Addition
K code — £2,000 is added to your taxable income (typically reflecting company car benefit, medical insurance or underpaid tax).
K274 — K Code £2,740 Addition
K code — £2,740 is added to your taxable income each year, usually because benefits in kind (e.g. company car) outweigh your Personal Allowance.
K475 — K Code £4,750 Addition
K code — £4,750 is added to your taxable income. Common for employees with a mid-range company car or modest employer benefits.
Check your own code: enter any HMRC tax code into the free tax code checker — it decodes the letters and number, shows your Personal Allowance, and estimates your take-home using 2025-26 or 2026-27 rates.
For the full plain-English guide to every UK tax code letter, prefix and suffix, see UK Tax Codes Explained 2026-27.
Sources
Tax code rules from gov.uk/tax-codes. Income tax rates from HMRC. Effective tax figures computed live from central configuration — correct for 2025-26.