Search HMRC’s website for “P11D” and you immediately see two forms — P11D and P11D(b) — and a thicket of guidance about which goes when. The two forms do completely different jobs and you generally need both, but only one P11D(b) per PAYE scheme regardless of how many employees received benefits. Here is the plain-English version.
The Short Answer
| Form | What it does | How many do you file? |
|---|---|---|
| P11D | Lists one employee’s reportable benefits in kind for the tax year | One per employee with non-payrolled benefits |
| P11D(b) | Declares total Class 1A National Insurance the employer owes on those benefits | One per PAYE scheme, regardless of headcount |
Both are due to HMRC by 6 July following the end of the tax year (so 6 July 2026 for the 2025-26 tax year). The Class 1A NIC declared on the P11D(b) is then paid by 22 July (electronic) or 19 July (post).
P11D — One Per Employee
The P11D records the cash equivalent of each benefit your employer provided to you during the tax year. Each employee with reportable benefits gets their own form. The employee receives a copy by the same 6 July deadline, and HMRC uses the figures to adjust the employee’s tax code for the following year so income tax on the benefits is collected through PAYE.
What goes on a P11D includes (each in its lettered section):
- A — Assets transferred to employee (e.g. car given outright)
- B — Payments made on behalf of employee
- C — Vouchers and credit cards
- D — Living accommodation
- E — Mileage allowances above HMRC approved rates
- F — Cars and car fuel
- G — Vans and van fuel
- H — Beneficial loans (over £10,000)
- I — Private medical and dental treatment
- J — Qualifying relocation expenses over £8,000
- K — Services supplied
- L — Assets placed at the employee’s disposal (e.g. yacht, holiday flat)
- M — Other items (e.g. subscriptions, professional fees, gym memberships)
- N — Expenses payments
Trivial benefits (£50 or less each, capped at £300/year for directors of close companies) and payrolled benefits are excluded — they do not appear on the P11D.
P11D(b) — One Per PAYE Scheme
The P11D(b) is the employer’s annual return declaring the total Class 1A National Insurance contributions due. Class 1A NIC is charged on most benefits in kind at 15% for 2025-26 and 2026-27 (raised from 13.8% with effect from 6 April 2025).
It is one form per PAYE scheme regardless of how many P11Ds you file. A 5-employee business with company cars files 5 P11Ds and 1 P11D(b). A 500-employee business with widespread benefits files up to 500 P11Ds and 1 P11D(b).
The P11D(b) has five sections: an introduction, a list of employees who may need a P11D, summary totals (where you enter the Class 1A NIC due and any adjustments to arrive at the NIC payable), and a declaration that the entries are correct.
Which Benefits Are Class 1A and Which Are Not?
Not every P11D entry attracts Class 1A NIC — this is one of the most-confused points. The general rule is:
| Benefit type | Goes on P11D? | Class 1A on P11D(b)? |
|---|---|---|
| Company car (BIK) | Yes | Yes |
| Private medical insurance | Yes | Yes |
| Gym membership | Yes | Yes |
| Beneficial loan over £10,000 | Yes | Yes |
| Living accommodation | Yes | Yes |
| Childcare vouchers (legacy) | Yes | No (Class 1 already paid via payroll) |
| Mileage payments above HMRC rates | Yes | No (Class 1 via payroll on excess) |
| Round-sum expense allowances | Yes | No (Class 1 via payroll) |
The Class 1 vs Class 1A distinction matters because Class 1 employee NIC has already been deducted at source on the payslip — you cannot then charge Class 1A on the same money.
Common Filing Mistakes
Filing P11Ds without P11D(b): HMRC’s online portal does not allow this — but commercial software occasionally lets you submit P11Ds and forget the P11D(b). The penalty is then £100 per 50 employees per month for the missing P11D(b), even though all P11Ds arrived on time.
Filing P11D(b) with the wrong total: the Class 1A figure must reconcile to the sum of Class-1A-bearing items across all P11Ds. HMRC’s computer system flags discrepancies and triggers a compliance check.
Treating payrolled benefits as P11D items: from April 2016 employers could payroll benefits voluntarily, and mandatory payrolling is due to start in April 2027 (see below). Payrolled benefits go through PAYE in real time and do not appear on the P11D — but they DO still appear on the P11D(b) total because Class 1A NIC remains the employer’s annual liability.
Missing the registration window: you can only payroll benefits you registered to payroll before 6 April 2026; HMRC no longer takes new voluntary registrations, so an employer that did not register stays on P11Ds until mandatory payrolling starts.
Forgetting the Class 1A payment: filing P11D(b) on 6 July does NOT pay the NIC. The payment is a separate action by 22 July.
Worked Example: 30-Person Tech Startup
Scenario: A 30-person tech startup gives 8 employees electric company cars (Tesla Model 3s, P11D value £40,000 each, 4% BIK rate for 2026-27) and provides private medical insurance to all 30 employees at £900 per person per year.
Step 1 — Cash equivalent per employee:
| Employee group | Car BIK | Medical BIK | Total per employee |
|---|---|---|---|
| 8 with car + medical | £40,000 × 4% = £1,600 | £900 | £2,500 |
| 22 with medical only | £0 | £900 | £900 |
Step 2 — Number of P11Ds: 30 (one per employee receiving any benefit).
Step 3 — P11D(b) totals:
- Total Class 1A benefits: (8 × £2,500) + (22 × £900) = £20,000 + £19,800 = £39,800
- Class 1A NIC at 15%: £39,800 × 15% = £5,970
Step 4 — Filing & payment: by 6 July submit 30 P11Ds and 1 P11D(b) declaring £39,800 / £5,970. By 22 July, pay £5,970 to HMRC.
If the company instead payrolled both car and medical from April 2025 (registered before 5 April 2025), there would be zero P11Ds but still one P11D(b) declaring the same £39,800 / £5,970.
What Changes in 2026-27 — and What’s Coming in 2027-28
Mandatory payrolling of benefits in kind was originally planned for 6 April 2026, but HMRC delayed it by a year and split it into two phases. Phase 1, from 6 April 2027, mandates payrolling for company cars, car fuel, vans, van fuel, and employer-provided medical benefits. Phase 2, from 6 April 2028, brings in most other benefits in kind. For 2026-27 itself, payrolling remains entirely voluntary — employers not already payrolling must keep filing P11Ds as normal. One practical wrinkle: HMRC closed the voluntary payrolling service to new registrations from 6 April 2026, so an employer can now only payroll benefits it had already registered to payroll before that date.
Beneficial loans and living accommodation are not in either phase — they cannot be payrolled today and stay on the P11D, and HMRC says mandatory payrolling for them will be confirmed at a later date.
The P11D(b) and Class 1A NIC payment continue indefinitely — the legal mechanism for charging employer NI on benefits has not changed, only the reporting route. Expect further HMRC guidance as the phased 2027-28 rollout approaches.
Quick Reference
- One P11D per employee with non-payrolled benefits, all due 6 July
- One P11D(b) per PAYE scheme, also due 6 July, declaring total Class 1A NIC
- Class 1A NIC payment by 22 July (electronic) — separate action from filing
- Use HMRC PAYE Online or commercial software — HMRC accepts paper P11Ds only if you’ve stopped trading or are digitally exempt
Use our P11D calculator to work out the cash equivalent of each benefit and the total Class 1A NIC liability before you file. For the wider deadline and penalty regime see our P11D deadline 2026 guide.
Sources
- GOV.UK — Expenses and benefits for directors and employees: a tax guide (480)
- GOV.UK — Class 1A National Insurance contributions on benefits in kind (CWG5)
- GOV.UK — Payrolling: tax employees’ benefits and expenses through your payroll — confirms registration to voluntarily payroll closed to new employers from 6 April 2026
- GOV.UK — The phased introduction of mandatory payrolling for benefits in kind — mandatory payrolling delayed one year from the original April 2026 date; now phased in from 6 April 2027
- HMRC PAYE Online for employers