A P11D is the form an employer files with HMRC to report benefits in kind — company cars, private medical cover, interest-free loans and the rest — given to employees during the tax year. It is filed once a year, by 6 July following the tax year, alongside a P11D(b) summarising the employer's Class 1A National Insurance bill on those benefits. The employee pays income tax on the benefit's cash value; the employer pays Class 1A NIC at 15%.
That system is now in its final years. Mandatory payrolling of benefits starts phasing in from April 2027, which will eventually retire the P11D for most benefits. But "eventually" is doing a lot of work in that sentence — for now the July cycle still runs, the penalties are still automatic, and the transition itself needs planning. Here is the whole picture.
What goes on a P11D
Reportable, non-exempt benefits provided to an employee (or director) that have not been payrolled: company cars and fuel, vans with private use, private medical and dental insurance, gym memberships, beneficial loans over £10,000, employer-provided accommodation, non-exempt travel and subsistence. Each benefit type has its own valuation rules — car benefit runs off list price and CO2 emissions, loans off the official rate of interest, most others off cost to the employer.
Two things routinely stay off the form when they should not. Directors' overdrawn loan accounts that drift past £10,000 create a beneficial loan benefit — unless interest at least at HMRC's official rate is actually being charged and paid, which in accidental overdrafts it never is — and the accident is no defence. And benefits provided by a third party or through salary sacrifice have their own rules — under an optional remuneration arrangement, the taxable figure is generally the higher of the benefit value and the salary given up.
Genuinely trivial perks are exempt: £50 or less a head, not cash or a cash voucher, not a reward for work, not contractual. Directors of close companies have a £300 annual cap on trivial benefits; everyone else has no cap but the per-benefit conditions still bite.
The deadlines that matter
- 6 July — P11Ds to HMRC and copies to employees; P11D(b) filed
- 19 July (post) or 22 July (electronic) — Class 1A NIC paid
- Class 1A rate for 2026/27: 15%, matching the main employer NIC rate
Late P11D(b)s attract an automatic £100 per month per 50 employees (or part thereof) — HMRC issues these in batches, so a form that is four months late arrives as a £400-plus bill in one envelope. Late Class 1A payment adds percentage surcharges and interest on top. Careless errors on the forms themselves can be penalised as a proportion of the tax understated, which is why "we copied last year's figures" is a riskier filing strategy than it feels.
Made a mistake? Amended P11Ds can be filed, and an amendment volunteered before HMRC notices is treated very differently from one extracted during a compliance check. If a benefit has been missed for several years — the drifting loan account is the usual suspect — take advice on a disclosure rather than quietly fixing the current year.
Payrolling benefits: the current, voluntary version
Employers registered for voluntary payrolling add each benefit's value to taxable pay across the year, so the tax is collected in real time: employees avoid the lagged tax-code adjustments that make P11D benefits so unpopular, and the July P11D run shrinks — though the P11D(b) and Class 1A payment still happen annually.
The registration mechanics changed this year, and most guidance online is out of date: HMRC's old online registration service closed to new registrants from 6 April 2026 — it now serves only employers who registered before that date. For everyone else, the next door opens in November 2026, when registration begins for voluntary payrolling from the following tax year of the benefits outside the 2027 mandate — including, for the first time, beneficial loans and living accommodation.
What becomes mandatory in April 2027 — and what doesn't yet
Mandatory payrolling was originally pencilled in for April 2026, then delayed and phased. As it stands: from 6 April 2027, company cars, car fuel, vans, van fuel and employer-provided medical benefits must be payrolled. Most remaining benefit types follow from April 2028, with loans and accommodation expected to keep a reporting route outside the mandate. HMRC has signalled a light-touch penalty approach for the first year, deliberate errors excepted — and, as the repeated slippage suggests, the fine print is still moving, so build to the direction of travel rather than to any single announcement.
The sensible move for employers with cars or medical cover is not to wait for the mandate: use the November 2026 registration window to payroll voluntarily from the next tax year, iron out the data flows — fleet lists, insurer schedules, starters and leavers mid-year — while mistakes are cheap, and let the mandate arrive as a non-event. The employers who will have a bad 2027 are the ones converting a decade of spreadsheet P11D habits into real-time payroll in a single April.
PSAs: the third rail of benefits reporting
Some benefits are impractical to put on anyone's P11D — staff entertaining above the exemptions, shared gifts, minor perks across a large workforce. A PAYE Settlement Agreement lets the employer settle the tax and NIC on these itself: apply by 5 July following the tax year, pay by 19 October (22 October electronically). The grossed-up cost is real money — the employer is paying the employees' tax for them — but it beats issuing 400 P11Ds for a summer party that went £20 a head over the exemption.
Getting the annual cycle out of your way
Benefits reporting is a calendar problem more than a technical one: registration windows in spring, filing in early July, Class 1A mid-July, PSA in October, and now a two-year payrolling transition overlaid on all of it. Most of the failures we untangle started with nobody owning the calendar.
Our employment tax team runs P11D seasons, PSA negotiations and payrolling transitions for employers of every size, usually alongside PAYE services or fully outsourced payroll. If your July filing was a scramble this year, the transition planning conversation is worth having before the next registration window closes.