YF AccountingLast updated: 23 July 2026
5 min read
The P11D deadline for 2025/26 was 6 July 2026, and the Class 1A National Insurance payment was due by 22 July 2026 — both have now passed. If you have not filed or paid, the answer is simple: do it now. Late P11D(b)s attract £100 per 50 employees for each month outstanding, and unpaid Class 1A NIC picks up interest immediately and a 5% penalty if it is still unpaid 30 days after the due date. This guide covers how to put a late filing right — and how to use 2026/27 to get ready for mandatory payrolling of benefits, which arrives in April 2027.
What happens if you missed the 6 July P11D deadline?
If you provided taxable benefits in kind — company cars, private medical insurance, interest-free loans over £10,000, gym memberships and the like — during 2025/26 and have not yet filed, penalties are already accruing:
- Late P11D(b): an automatic £100 per 50 employees (or part batch of 50) for each full month the return is late. A small company with under 50 employees that files in mid-August is looking at £100; leave it until November and it is £400.
- Late P11Ds: HMRC can ask the tribunal to impose penalties of up to £300 per form, plus up to £60 a day for continued failure — in practice this is reserved for persistent non-filers, but it exists.
- Incorrect returns: careless or deliberate errors can attract penalties of up to 30%, 70% or even 100% of the tax lost.
The practical takeaway: penalties are charged per month, so filing this week rather than next month genuinely saves money. File through your payroll software or HMRC’s PAYE Online service, and remember employees must be given their copy of the P11D information too.
What about the Class 1A NIC that was due on 22 July?
Class 1A National Insurance on 2025/26 benefits was due by 19 July 2026 by post, or 22 July 2026 electronically. The rate for 2025/26 is 15% of the cash equivalent value of the benefits — the same rate that applies to employer Class 1 contributions.
If you have not paid yet:
- Interest runs from the due date until you pay — there is no grace period on interest.
- 5% penalty on the amount still unpaid 30 days after the due date (around 22 August 2026).
- 10% penalty if still unpaid after six months, rising to 15% after twelve months.
So there is a real deadline hiding inside the missed one: pay before late August and you cap the damage at interest only. If cash flow is the problem, contact HMRC about a Time to Pay arrangement before the 30-day mark rather than after it.
Do you need to file if you payrolled benefits or provided none?
If you registered for voluntary payrolling before 6 April 2025 and taxed benefits through payroll during 2025/26, you do not file P11Ds for those benefits — but you still needed a P11D(b), because Class 1A NIC is settled annually rather than through the payroll.
If HMRC sent you a P11D(b) notice but you provided no benefits at all, tell them a nil return is due using the online “no return of Class 1A” form. Ignoring the notice leads to penalty letters for a return you never owed — an entirely avoidable headache.
When does mandatory payrolling of benefits start?
Now the forward-looking part. Mandatory payrolling of benefits in kind starts in April 2027 — pushed back a year from the original April 2026 start date to give employers and software providers time to prepare. It was the right call; the earlier timetable was tight.
From the 2027/28 tax year, most benefits will be reported through Real Time Information and taxed through PAYE in the period they are provided, rather than in arrears via a P11D. Two exceptions remain:
- Employment-related living accommodation
- Beneficial loans (interest-free or low-interest — including director’s loans over £10,000)
These can still be reported on a P11D after April 2027, and Class 1A NIC will still be summarised annually on a P11D(b). So the P11D is shrinking dramatically, but not quite dying.
How should you prepare during 2026/27?
The current tax year is your preparation window. The deadline to register for voluntary payrolling for 2026/27 has passed (it was 5 April 2026), so if you are not already payrolling, your realistic path is to register by 5 April 2027 so you start 2027/28 ready rather than scrambling. In the meantime:
- Audit every benefit and expense you provide, so nothing slips through the cracks
- Ask your payroll software provider about their April 2027 roadmap
- Review tax codes and current notices of coding for affected employees
- Brief your team on what real-time tax on benefits will look like in their payslips
- Consider whether any beneficial loan or accommodation arrangement should be restructured or repaid before it complicates things
If you are already payrolling voluntarily, treat 2026/27 as a live rehearsal: check the cash equivalents calculate correctly and that your year-end reconciliation works cleanly. And for directors of small companies, this is a good moment to check the benefits you take are actually tax-efficient — the £50 trivial benefits exemption remains one of the simplest planning tools available. Our payroll and PAYE guide covers the wider picture.
Frequently asked questions
How much is the penalty for a late P11D(b)?
£100 per 50 employees for each full month the return is late, charged automatically. For most small businesses that means £100 per month. HMRC typically issues the first penalty notice once the return is three months late, so a bill of £300 landing in October is common — filing now stops the meter.
What happens if I pay Class 1A NIC late?
Interest runs from the 19 or 22 July due date until payment. On top of that, a 5% penalty applies to anything still unpaid 30 days after the due date, rising to 10% at six months and 15% at twelve months. Paying before late August 2026 limits the cost to interest alone.
Is 2025/26 the last year I need to file P11Ds?
No — 2026/27 is the last full P11D year, with forms due by 6 July 2027. Mandatory payrolling starts from April 2027, so the 2027/28 year is the first under the new regime. Even then, living accommodation and beneficial loans can still be reported on a P11D, and the P11D(b) survives for Class 1A NIC.
What counts as a benefit in kind for P11D purposes?
Anything of value provided to an employee or director outside payroll: company cars and fuel, private medical insurance, interest-free loans over £10,000, gym memberships, and most non-trivial gifts. Trivial benefits under £50 (with conditions) and most business expenses covered by exemptions do not need reporting.
What is mandatory payrolling of benefits?
From April 2027, employers must report most benefits in kind through Real Time Information and collect the income tax through PAYE as the benefit is provided, instead of reporting it after year end on a P11D. Employees pay the tax in-year through their payslip rather than through an adjusted tax code the following year.
Need a hand catching up — or getting ahead?
If you have a late P11D to sort or want a clear plan for mandatory payrolling, we can take it off your plate. We run payroll and benefits reporting on fixed fees — limited companies from £50 a month, sole traders from £35 a month — with no hourly billing.
Book a free, no-obligation call or ring 0161 531 0959 and we will get you straight with HMRC.
This article is general information, not personal tax advice. Penalty figures correct at July 2026 — for advice on your own situation, please get in touch.
Founder of YF Accounting — a fixed-fee, fully digital accountancy practice in Manchester serving SMEs, sole traders and landlords across the UK. One point of contact, unlimited support, no surprise bills.
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