P11D Season 2026 — What Benefits in Kind Mean for Your Tax Bill
By TaxHelper Editorial · Last updated 11/06/2026
Every year by 6 July, employers must file P11D forms with HMRC — and give copies to employees — reporting any taxable benefits received during the previous tax year. If you have a company car, private medical insurance, a cheap company loan or a gym membership paid for by your employer, a P11D affects how much tax you pay. Here is everything you need to know for 2026.
What Is a P11D?
A P11D is a form submitted by your employer to HMRC that details benefits in kind (BiK) — things of financial value provided to you by your employer that are not part of your cash salary. HMRC uses the taxable value of these benefits to adjust your tax code for the following year, collecting any additional income tax owed through your monthly payslips.
The P11D covers the tax year just ended (April–March). So the P11Ds issued by 6 July 2026 relate to benefits received in 2025/26 and will affect your 2026/27 tax code — meaning any extra tax is spread across your current pay packets.
Which Benefits Are Taxable?
Not all employer-provided benefits trigger a tax charge. Here are the most common ones:
| Benefit | Taxable? | Notes |
|---|---|---|
| Company car (with private use) | Yes | Based on list price × CO2 percentage |
| Company car fuel (for private use) | Yes | Fixed benefit of £27,800 × CO2 percentage in 2026/27 |
| Private medical insurance | Yes | Based on employer's premium cost |
| Employer gym membership (offsite) | Yes | Cost to employer is taxable value |
| Company loans over £10,000 | Yes | Tax on notional interest at HMRC's official rate (2.5%) |
| One mobile phone per employee | No | Completely exempt |
| Work laptop (mainly for work use) | No | Exempt if primarily for work |
| Cycle to Work bike and equipment | No | Exempt under the qualifying scheme |
| Workplace canteen open to all staff | No | Must be available to all employees equally |
How Benefits in Kind Affect Your Tax Code
The taxable value of your benefits is added to HMRC's estimate of your non-PAYE income, which in turn reduces your Personal Allowance in your tax code. For example:
- Private medical insurance worth £900/year changes your code from 1257L to approximately 1167L — a reduction of 90 in the code number, costing you £180/year in extra tax (20% of £900).
- A company car with a taxable BiK value of £5,000/year reduces your code by 500 — costing a basic-rate taxpayer £1,000/year in extra income tax.
Check your current tax code using our tax codes guide to see whether benefit deductions are already baked in — and whether the amount HMRC is using matches your actual benefits.
Company Car BiK Rates: Electric vs Petrol in 2026/27
Company car benefit-in-kind tax is calculated as: List price × appropriate percentage. The appropriate percentage is determined by the car's CO2 emissions (or, for electric vehicles, a government-set rate).
For 2026/27:
- Fully electric vehicles: 3% appropriate percentage. A £40,000 electric company car generates a BiK value of £1,200. A basic-rate taxpayer pays £240/year in extra income tax.
- Petrol 121–130g/km CO2: 28% appropriate percentage. A £30,000 petrol car generates a BiK value of £8,400. A basic-rate taxpayer pays £1,680/year in extra tax.
- Petrol 131–145g/km CO2: 30–32% appropriate percentage. A £30,000 car in this range generates a BiK of £9,000–£9,600, costing a basic-rate taxpayer £1,800–£1,920/year.
The difference is stark. An employee in an electric company car pays roughly seven times less in BiK tax than someone in a comparable petrol car. This is why salary sacrifice electric vehicle schemes have become extremely popular — the low BiK rate combined with the salary sacrifice NI saving makes running a new EV through an employer almost always cheaper than buying one privately.
What to Do If Your P11D Is Wrong
Employers sometimes report incorrect benefit values — particularly for company cars (wrong list price, incorrect CO2 band) or medical insurance (using the wrong premium year or including family members who did not have cover all year). If your P11D is wrong, follow these steps:
- Check your P11D copy. Your employer must give you a copy by 6 July. Review each benefit listed and verify the values against your contract, car documentation, or HR records.
- Contact your employer's payroll or HR team. If the error is in the benefit values, your employer must submit a corrected P11D (P11D(b)) to HMRC. This can be done at any point.
- Contact HMRC if your tax code does not update. Call 0300 200 3300 with your NI number and employer's PAYE reference. HMRC will amend your code once the corrected P11D is received.
- File a Self Assessment return if you are already registered. You can override the P11D figures in your return with the correct values and HMRC will reconcile the difference.
If you overpaid tax because of an incorrect P11D in a previous year, you can claim a refund through your Personal Tax Account or by writing to HMRC. The standard time limit for reclaims is four years from the end of the relevant tax year.
Use our salary calculator to model how a P11D benefit adjustment would affect your take-home pay — enter your salary and try different tax code values to see the monthly impact.