P11D: What Are Benefits in Kind and Do You Owe Tax on Them?
By TaxHelper Editorial · Last updated 11/06/2026
If your employer provides anything beyond your cash salary — a company car, private health insurance, a gym membership — it may be a taxable benefit in kind. These are reported on a P11D form and affect your income tax.
What Is a P11D?
A P11D is a form your employer submits to HMRC by 6 July after the tax year, reporting taxable benefits you received. HMRC uses it to adjust your tax code for the following year, collecting the tax across your payslips.
Which Benefits Are Taxable?
| Benefit | Taxable? |
|---|---|
| Company car (personal use) | Yes — percentage of list price based on CO2 |
| Private health insurance | Yes — based on employer's cost |
| Loans over £10,000 at below-market rates | Yes — on notional interest |
| Employer gym membership (off-site) | Yes |
| One mobile phone per employee | No |
| Workplace canteen open to all staff | No |
| Cycle to Work bike | No |
How Benefits Affect Your Tax Code
The taxable value of benefits is built into your code by reducing your Personal Allowance. Private health insurance worth £800 changes your code from 1257L to approximately 1177L — costing you an extra £160/year in tax (20% of £800), spread across monthly payslips.
Company Car Tax — Worked Example
Petrol car, £25,000 list price, 130g/km CO2 — appropriate percentage of 28%. Taxable benefit: £7,000/year. A basic-rate taxpayer pays an extra £1,400/year in income tax.
What If Your P11D Is Wrong?
Check your copy (issued by your employer by 6 July). Verify the benefit value and dates. If incorrect, ask your employer to submit a corrected P11D. Contact HMRC on 0300 200 3300 if your code does not update. See our tax code checker to verify what your current code implies.