If you’re an employer providing benefits in kind — company cars, private medical insurance, beneficial loans — three deadlines matter every July. Miss them and HMRC charges automatic penalties that compound month after month. This guide covers each deadline, exactly what’s due, and how the penalty regime works for the 2025-26 tax year.
The Three July Deadlines
For the 2025-26 tax year (ended 5 April 2026), here is what HMRC expects:
| Deadline | What is due | Who files / pays |
|---|---|---|
| 6 July 2026 | P11D forms — one per employee with reportable benefits | Employer (copy to employee same day) |
| 6 July 2026 | P11D(b) form — employer’s declaration of total Class 1A NIC liability | Employer |
| 22 July 2026 | Class 1A National Insurance payment | Employer (electronic). 19 July if paying by post. |
If 6 July or 22 July falls on a weekend, the deadline does not move forward — HMRC expects submission by the prior working day. In 2026, both 6 July and 22 July are weekdays (Monday and Wednesday respectively), so no adjustment is needed.
What Goes on a P11D vs a P11D(b)
Many employers treat these as one filing but they are two separate forms with two separate purposes.
P11D is filed per employee who received a non-payrolled benefit during 2025-26. It lists the cash equivalent of each benefit. There is no de-minimis — even a £40 benefit triggers a P11D unless it qualifies as a trivial benefit under £50.
P11D(b) is the employer’s annual return declaring total Class 1A NIC liability across all employees. One P11D(b) per PAYE scheme, regardless of how many P11Ds you file.
You can file P11D(b) without any P11Ds (if you payroll all benefits) but you cannot file P11Ds without a P11D(b).
Late Filing Penalty for P11D(b)
The P11D(b) penalty is the headline number employers track. It is structured as £100 per 50 employees (or part thereof) for every month or part-month of delay, capped at 12 months.
| PAYE scheme size | Penalty per month late |
|---|---|
| 1–50 employees | £100 |
| 51–100 employees | £200 |
| 101–150 employees | £300 |
| 151–200 employees | £400 |
| Each additional 50 employees | + £100 |
A 200-person business that files P11D(b) on 6 October 2026 (3 months late) faces 3 × £400 = £1,200. The same business filing in October 2027 (12 months late) hits the cap at £4,800.
For a small employer with say 8 staff, the penalty is £100 per month — recoverable but visible. The risk is the deadline passing unnoticed during summer holidays.
Late Filing Penalty for Individual P11Ds
Individual P11D forms attract a separate penalty regime under TMA 1970 s98:
- Initial penalty: up to £300 per P11D form not filed by 6 July
- Continued failure: up to £60 per day after the initial penalty notice
In practice HMRC rarely uses the daily £60 rate against ordinary employers, but it is statutory and has been used in fraud or repeat-offender cases.
Inaccurate P11D Penalty
A P11D filed on time but with errors triggers a separate penalty under the inaccuracy regime (FA 2007 Sch 24):
| Behaviour | Penalty range (% of tax / NIC at risk) |
|---|---|
| Careless | 0–30% (reducible to 0% for unprompted disclosure) |
| Deliberate but not concealed | 20–70% |
| Deliberate and concealed | 30–100% |
The “tax at risk” is the additional income tax the employee would owe plus the additional Class 1A NIC the employer would owe. For a £20,000 understated company car BIK at higher rate, that is roughly £8,000 income tax + £3,000 Class 1A — so a careless inaccuracy could cost £3,300 in penalty alone before unpaid tax.
Late Payment Penalty for Class 1A NIC
Class 1A NIC paid after 22 July (electronic) attracts:
- Interest at HMRC’s late-payment rate (currently 7.5% per year, set in line with Bank of England base rate + 2.5%)
- 5% penalty if still unpaid after 30 days
- Further 5% penalties at 6 months and 12 months overdue
This stacks on top of any P11D(b) late filing penalty.
Worked Example: Small Business Forgets the Deadline
Scenario: A 12-person consultancy provides 4 employees with company cars and 8 with private medical insurance. Total Class 1A NIC liability for 2025-26 is £6,800. The director files everything on 10 September 2026 — over 2 months late.
| Item | Amount |
|---|---|
| P11D(b) late filing penalty (1–50 staff bracket, 3 months part-counted) | £300 |
| Class 1A NIC late payment interest (50 days @ 7.5%) | £70 |
| Class 1A NIC late payment 5% penalty (over 30 days late) | £340 |
| Total penalty + interest | £710 |
The 12 individual P11Ds are also technically late but for one-off small-employer cases HMRC typically does not raise the s98 penalty if P11D(b) is on time — here both are late, so the £300 P11D penalty risk exists but is rarely enforced for first-time small offenders.
Penalty Appeals
You can appeal a P11D or P11D(b) late filing penalty if you have a reasonable excuse. Accepted excuses include:
- Serious illness or bereavement of the person responsible for the filing
- HMRC online services failure on the deadline day (with proof)
- Fire, flood, or theft preventing access to records
- Postal disruption (only for P11Ds filed by post — P11Ds since April 2023 must be filed online for most employers)
Not accepted: pressure of work, lack of awareness of the deadline, software issues that could have been resolved, or the person responsible leaving the business.
Appeal in writing within 30 days of the penalty notice via the address on the notice or through your HMRC online account.
What Employees Should Do
If you are an employee waiting for your P11D copy:
- By 6 July you should have a paper or PDF P11D from your employer. If not, chase your payroll team.
- Check the cash equivalent figures against your records — common errors include incorrect car list price (should include options and delivery), forgotten medical insurance premium increases, and incorrectly classified loans.
- After 6 July, log in to your Personal Tax Account and check your tax code for the current year — HMRC will adjust it to collect the BIK tax via PAYE on a forward-looking basis.
- If you spot an error on your P11D, ask your employer to file a correction. Do not amend the values yourself on a Self Assessment return without the corrected P11D — this triggers HMRC review.
Action Checklist for Employers
Lock these dates in your payroll calendar now:
- By 30 June: P11D(b) value reconciled to payroll records; P11D drafts reviewed by each employee
- By 6 July: P11D(b) and P11Ds submitted via HMRC PAYE Online or commercial software; copies issued to employees
- By 19 July: Class 1A NIC payment scheduled for 22 July (BACS / Faster Payments / direct debit)
- By 22 July: Class 1A NIC cleared at HMRC
For 2026-27 onwards, mandatory payrolling of most benefits will eliminate the need to file individual P11Ds — but P11D(b) and Class 1A NIC remain. Use our P11D calculator to work out the cash equivalent of each benefit and the total Class 1A NIC liability before you file.