P11D Explained UK: Benefits in Kind, Tax Code Impact, 2026 Rules

A P11D is the form your employer sends to HMRC each year listing the benefits in kind (BIK) and expenses you received that aren't already taxed through PAYE. It's one of the most frequently misunderstood UK tax documents - partly because most employees never see it, but its consequences land on your tax code months later.

This guide explains exactly what's on a P11D, how the figures translate into your tax code, what to check, and what to do if you suspect an error.

What goes on a P11D

A P11D lists taxable benefits and expenses that your employer provided but didn't process through payroll. The most common items:

• Company car (the largest item for most P11D-affected employees - see our company car tax guide).
• Private medical insurance (BUPA, AXA, Vitality etc.).
• Living accommodation (employer-provided housing).
• Beneficial loans (interest-free or low-interest loans above £10,000).
• Vouchers and credit cards (where not processed through payroll).
• Assets transferred to you (e.g. an old company laptop given as a leaving gift).
• Subscriptions that don't qualify for relief (gym memberships, club memberships).
• Travel and subsistence above HMRC's exempt limits.
• Employer-provided fuel for a company car (separately calculated).

Items that don't go on a P11D:

• Salary, bonuses, commission, overtime - all PAYE.
• Pension contributions to a registered scheme (tax-free at source).
• Workplace nursery / Tax-Free Childcare (specifically exempt).
• Approved mileage payments at HMRC AMAP rates (45p/25p/24p/20p).
• Trivial benefits (gifts under £50 a head, with conditions).
• Cycle-to-work / EV-charging at workplace (specifically exempt).

The two key dates

Date	Action
6 July following the tax year end	Employer must give you (the employee) a copy of your P11D, OR the equivalent information by another method.
6 July following the tax year end	Employer must file the P11D with HMRC.
22 July	Employer must pay any Class 1A NIC owed on the BIK figures.

If your employer hasn't given you your P11D by 6 July, ask them. They are legally required to either provide a P11D or notify you that no P11D is needed (some benefits are now "payrolled" - see below).

The "payrolling" alternative

Since 2016 employers can opt to payroll benefits in kind instead of issuing a P11D. Where this happens:

• The taxable value of the benefit is added to your gross pay each period.
• PAYE tax is collected in the same period as the benefit is given.
• No P11D is needed for that benefit.
• Your tax code does NOT need adjusting for it.

This is now common for medical insurance, gym memberships and similar. From April 2026, payrolling becomes mandatory for most BIKs (the company-car charge remains optional to payroll for now).

If your benefits ARE payrolled, you should see a small line on your payslip labelled "BIK" or similar - that's the gross-up. If you don't see it, your benefits are still on the P11D path.

How a P11D affects your tax code

The P11D figures from year N-1 typically feed into your tax code for year N+1. The mechanism:

1. Your employer files your year N-1 P11D by 6 July of year N.
2. HMRC processes the figures and recalculates your Personal Allowance.
3. HMRC issues a P2 PAYE Coding Notice for year N+1 (typically January-March of year N).
4. Your tax code from 6 April year N+1 reflects the BIK adjustment.

Worked example: in 2024/25 you had £5,000 of taxable BIK (private medical + company car). Your 2025/26 tax code would normally be 1257L (£12,570 allowance). HMRC subtracts the £5,000 BIK from your allowance, giving £7,570. The new code becomes 757L.

Your monthly tax goes up because your tax-free allowance has dropped.

When you get a K-code

If your taxable benefits exceed your Personal Allowance (commonly because of a high-value company car + medical + accommodation), HMRC issues a K-code - a negative-allowance code.

For example: BIK of £18,000 against a £12,570 allowance gives a negative £5,430. Code becomes K543 (the prefix K means add £5,430 to taxable income each year, calculated on a cumulative basis through PAYE).

K-codes are capped: your employer cannot deduct more than 50% of your gross pay through PAYE in any single period. If your K-code calculation would exceed that, the under-collected tax carries forward to later periods or to year-end reconciliation.

What to check when your P11D arrives

1. Read every line. It's typically 1-3 pages. Compare each item against what you actually received.
2. Cross-check the company-car figures. The taxable value of a company car depends on its CO2 emissions, list price (P11D value) and your personal-use percentage. If any of these is wrong, the figure is wrong.
3. Check the dates. Benefits should be reported only for the periods they were actually provided. A car returned in December but reported as "full year" is a £2,000+ over-statement.
4. Check medical insurance scheme value. This should match your employer's premium (or your premium if salary-sacrificed) - not your individual notional value.
5. Check beneficial loans. If you had an interest-free or low-interest loan above £10,000 at any point, check the calculation. The official HMRC interest rate is 2.25% for 2026/27.
6. Sign in to your HMRC Personal Tax Account at gov.uk/personal-tax-account and confirm HMRC's record matches your employer's P11D.

Common errors

• Old benefits still showing. A car you returned in October but the P11D shows for the full year.
• Wrong CO2 banding for company car. EV (0g/km) vs petrol/diesel (much higher) bands change BIK by thousands.
• Medical insurance for a partner not deducted. Some employers report only the employee value; others include partner/family. Check the policy.
• Living accommodation mis-reported. Employer-provided housing is one of the most error-prone P11D items - the calculation involves rateable value, market rent, and council-tax adjustments.
• Loan balance averaging wrong. Beneficial loans are calculated on the average balance through the year. If you repaid early, the average should reflect that.

What to do if your P11D is wrong

1. Tell your employer in writing. They are legally responsible for the figures.
2. Ask them to issue a corrected P11D. They have until 6 July to do so without penalty (after that, penalties apply for late amendments).
3. If your employer won't correct it (rare, but happens), contact HMRC on 0300 200 3300 with your evidence. HMRC can recalculate your tax code based on what you actually received.
4. For substantial errors, an accountant or CTA-qualified tax adviser can negotiate with HMRC and your employer.

P11D vs P11D(b)

• P11D is your individual benefits report - given to you and HMRC.
• P11D(b) is your employer's summary form, used to calculate the employer's Class 1A NIC liability on all employees' BIKs combined. You don't see a P11D(b).

Class 1A NIC - paid by the employer, not you

Your benefits in kind incur Class 1A National Insurance Contributions at the employer rate (15% in 2026/27). This is paid by your employer, not by you. The cost shows up in your employer's accounts but never on your payslip.

Knowing this is useful because it explains why some employers limit the benefits they offer - the employer cost of a £5,000 BIK is £750 of Class 1A NIC on top of the £5,000 benefit itself.

Disclaimer

PayslipIQ provides automated educational guidance based on the figures you supply. It is not regulated tax advice. P11D errors and BIK calculations can be technically complex (especially for company cars, beneficial loans and accommodation). For substantial errors or unusual situations, consult a CTA-qualified tax adviser or your employer's accountancy team.