The P11D and P11D(b) for a tax year ending on 5 April must reach HMRC by 6 July, and the Class 1A National Insurance they declare must be paid by 22 July [1]. A late P11D(b) costs £100 per 50 employees for each month or part month it is outstanding, before any penalty or interest on late payment [1].
Those two dates anchor the employer's expenses and benefits calendar, but they are not the only ones. Employees must receive a copy of the information on the same 6 July deadline, PAYE Settlement Agreements run to their own timetable in July and October, and cheque payments must arrive three days earlier than electronic ones [1]. The Class 1A rate for 2026-27 is 15%, the same as the employer Class 1 rate, so a modest benefits bill quickly becomes a material payment [16].
The calendar is also about to change. Mandatory payrolling of benefits in kind begins on 6 April 2027 for company cars, fuel, vans and medical benefits, with most other benefits following a year later [9].
This guide sets out every P11D-related deadline in order, who has to meet each one, how penalties and interest are calculated, how to pay Class 1A correctly, how to correct a form after the deadline, and how the timetable shifts as benefits move into real-time reporting.
Key takeaways
- P11D forms, the P11D(b) and the employee's copy of the information are all due by 6 July after the end of the tax year [1].
- Class 1A National Insurance must be paid by 22 July, or by 19 July when paying by cheque [1].
- A late P11D(b) attracts a penalty of £100 per 50 employees for each month or part month of delay [1].
- PAYE Settlement Agreements must be agreed by 5 July and paid by 22 October (19 October by post) [12].
- Employers that payroll benefits still have to complete a P11D(b) for the Class 1A due [7].
- Mandatory payrolling starts on 6 April 2027 for cars, fuel, vans and medical benefits, and from 6 April 2028 for most other benefits [9].
The P11D calendar at a glance
The tax year runs from 6 April to 5 April. Every expenses and benefits deadline is set by reference to the end of that year, so the dates repeat on the same days each summer and autumn [4].
| Date (after the tax year ends on 5 April) | Action | Source |
|---|---|---|
| 5 July | Deadline to apply for a PAYE Settlement Agreement for the first year it applies | [12] |
| 6 July | Submit P11D forms and the P11D(b) to HMRC | [1] |
| 6 July | Give each employee a copy of the information reported | [1] |
| 6 July | Report the total Class 1A National Insurance owed | [1] |
| 19 July | Class 1A payment by cheque must arrive | [5] |
| 22 July | Class 1A payment by electronic methods must arrive | [5] |
| 19 October | PSA tax and Class 1B payment by post | [12] |
| 22 October | PSA tax and Class 1B payment by electronic methods | [12] |
The payroll itself carries on through this period. Employers that payroll benefits account for tax on them each pay day through the normal PAYE cycle, so the summer dates matter for them only for Class 1A [7].
The 6 July filing deadline
Three obligations share the 6 July date: the P11D for each employee with reportable benefits, the employer's P11D(b) return, and the copy of the information given to each employee [1]. Missing any one of them is a breach, but only the P11D(b) carries the automatic monthly penalty.
Who needs a P11D
A P11D is needed for each employee or director who received taxable expenses or benefits that were not payrolled during the year [7]. Common examples include company cars used for private journeys and fuel for private journeys [19], and medical treatment or insurance, where the reporting depends on the kind of cover and whether the employer pays the provider directly [20].
Several items fall outside the form. A trivial benefit costing £50 or less to provide is exempt, with an annual cap of £300 for directors of close companies [14]. Loans with a combined outstanding value below £10,000 throughout the tax year are also exempt [15], although loans made under a salary sacrifice arrangement must still be reported [15].
| Item | Treatment | Source |
|---|---|---|
| Trivial benefit costing £50 or less | Exempt, no P11D | [14] |
| Trivial benefits to a close company director above £300 in the year | Reportable | [14] |
| Loans below £10,000 throughout the year | Exempt | [15] |
| Loans made through salary sacrifice | Reportable | [15] |
| Company car with private use | Reportable | [19] |
| Business mileage in a company car at or below advisory fuel rates | No taxable profit, no Class 1A | [25] |
The P11D(b) and the employer declaration
The P11D(b) is the employer's own return. It reports the total Class 1A National Insurance owed on all benefits, whether reported on P11Ds or payrolled [1]. HMRC's payrolling guidance is explicit that an employer that payrolls a benefit "must still work out the Class 1A National Insurance contributions on benefits and complete form P11D(b)" [7].
An employer that provided no benefits but receives a P11D(b) reminder from HMRC should still respond rather than ignore it, because HMRC's penalty is tied to the return it expects. The deadline and penalty rules set out on GOV.UK apply to the P11D(b) as a return in its own right [1].
How to submit
The submission route depends on employee numbers. HMRC states that employers with fewer than 500 employees can "fill in and submit the forms through HMRC's PAYE Online service", while those with more than 500 employees submit through their payroll software [2]. PAYE Online handles P11D, P11D(b) and P46(car) returns [17].
Paper is no longer an everyday option. HMRC "will only accept paper forms if you have stopped trading", in which case the employer or an insolvency practitioner can submit paper versions [2]. For a business planning to close, the filing still falls due by 6 July after the tax year, so the records need to be preserved through the wind-down [3].
The employee's copy
Employees must receive a copy of the information reported about them by 6 July [1]. The figures matter to them because HMRC uses reported benefits to adjust their tax code, typically reducing the tax-free amount shown in the code [26]. An employee who completes a Self Assessment return also needs the cash equivalents to report the benefit correctly.
Most employers send a copy of the P11D itself or a statement in the same format. The guidance requires the information to be given, not a particular form [1], so a secure digital statement through a payslip portal meets the requirement as long as each employee can access it before the deadline.
The 22 July Class 1A payment deadline
Class 1A is an employer-only contribution charged on the taxable value of most benefits. For 2026-27, HMRC confirms that "the National Insurance Class 1A rate on expenses and benefits for 2026 to 2027 is 15%" [16]. An employer that provided benefits with a total taxable value of £20,000 therefore owes £3,000 of Class 1A.
Payment timing and weekends
Payment must be made "by 22 July each year for the previous tax year", or by 19 July when paying by post [5]. If the deadline falls on a weekend or bank holiday, the payment must arrive on the last working day before it, unless the employer pays by Faster Payments through online or telephone banking [5].
| Payment method | Usual time to reach HMRC | Source |
|---|---|---|
| Online or telephone banking (Faster Payments) | Same or next day, including weekends | [6] |
| CHAPS | Same working day within bank processing times | [6] |
| Bacs | 3 working days | [6] |
| Direct Debit set up before | 3 working days | [5] |
| Direct Debit not set up before | 5 working days | [5] |
| Cheque by post | Must arrive by 19 July | [5] |
The payment reference
Class 1A has its own reference. HMRC asks for a 17-character number that "starts with your 13-character Accounts Office reference number", followed by the tax year being paid and the digits 13 [6]. For Class 1A on benefits for 2024 to 2025, the suffix is 2513, as shown in HMRC's example table [6].
The payment must also be made separately. HMRC states that employers "must make a separate payment for Class 1A payments" and "cannot add them to a standard PAYE payment" [6]. A Class 1A amount added to the monthly PAYE remittance under the monthly reference is likely to be allocated to the wrong charge, leaving the Class 1A showing as unpaid.
Penalties and interest for missing the deadlines
The penalty regime has three layers: a fixed monthly penalty for a late P11D(b), surcharges and interest for late Class 1A payment, and penalties for inaccurate returns.
Late P11D(b) penalties
HMRC states: "You'll get a penalty of £100 per 50 employees for each month or part month your P11D(b) is late" [1]. The penalty scales with the size of the workforce rather than with the Class 1A due, so a large employer with few benefits can face a substantial charge [1].
Because a part month counts as a full month, a return filed on 7 July carries the same first-month penalty as one filed on 5 August [1]. HMRC also warns that employers will be "charged penalties and interest if you're late paying" [1].
Late payment penalties on Class 1A
For Class 1A and Class 1B, HMRC sets the "penalty date" at 30 days after the due date [18]. A 5% penalty applies if the full amount has not been paid within 30 days, an additional 5% if it remains unpaid after 6 months, and a further 5% after 12 months [18].
Late payment interest
Interest runs from the due date until payment, separately from penalties. HMRC's published rates show late payment interest "set at base rate plus 4% from 6 April 2025", up from base rate plus 2.5% previously [13]. The rate moves with the Bank of England base rate, so the figure applied to a late Class 1A payment depends on when it is paid [13].
Inaccurate returns
A return filed on time can still attract a penalty if it is wrong. HMRC warns that an employer may have to pay a penalty if it "carelessly or deliberately" gives inaccurate information that results in not paying enough tax or over-claiming reliefs [2]. Keeping supporting records is the main defence, and they must be kept "for 3 years from the end of the tax year they relate to" [3].
PAYE Settlement Agreements and their own timetable
A PAYE Settlement Agreement (PSA) lets an employer settle the tax and National Insurance on minor, irregular or impracticable benefits in one annual payment, so those items do not appear on P11Ds [11]. The PSA has two deadlines of its own, both later than the P11D date.
Applying for a PSA
HMRC states that the deadline for applying is "5 July following the first tax year it applies to" [12]. The application deadline falls one day before the P11D deadline, so an employer deciding whether to move an item into a PSA has to make that decision before finalising its P11Ds [11].
Paying under a PSA
The tax and Class 1B National Insurance owed under a PSA must be paid "by 22 October after the tax year the PSA applies to (19 October if you pay by post)" [12]. Class 1B is charged at 15% for 2026-27, the same rate as Class 1A [16].
Correcting a P11D after the deadline
Errors found after submission are corrected online. HMRC asks employers to "fill in both online correction forms" to fix an error, report benefits for earlier tax years or notify changes [2].
Totals, not differences
The corrected P11D(b) must show the full liability. HMRC instructs employers to "include the total amount of Class 1A National Insurance you need to pay - not the difference from your previous version" [2]. Any additional Class 1A is then paid with the correct reference for the tax year concerned [6].
Exemptions replaced dispensations
Older payroll processes sometimes rely on dispensations to keep expenses off the P11D. HMRC confirms that "exemptions have replaced dispensations" and that employers "cannot apply for a dispensation any more" [21]. Expenses paid at benchmark rates or reimbursed at cost fall under the exemption instead, provided the records support them [3].
How mandatory payrolling changes the deadlines
The P11D calendar described above is entering its final years for the most common benefits. HMRC's draft guidance confirms that benefits in kind will be reported "in real time, through payroll software, from April 2027" [8].
The two phases
Employers will also have the option to exclude globally mobile employees from mandatory payrolling from 6 April 2027, and should continue to report for them on P11D and P11D(b) [8]. HMRC states that final guidance for phase 1 is due to align with Autumn Budget 2026 [9].
Class 1A moves into RTI
The largest change for the calendar is Class 1A. Under the new rules, Class 1A "will be reported by a different field in Real Time Information (RTI)" [10], and associated Class 1A contributions must be payrolled in real time from 6 April 2027 [8]. Where an employee has no earnings in a period, the employer still sends details on a Full Payment Submission and pays the Class 1A due [10].
In practice, the 22 July lump sum gives way to monthly Class 1A payments alongside PAYE for benefits within scope. Benefits provided up to 5 April 2027 remain on the existing year-end process, so the 6 July and 22 July dates still apply to the last full year of P11D reporting for cars and medical cover.
Preparing the payroll
Voluntary payrolling through HMRC's online registration service is now limited: employers "can only use the online service if you registered to payroll benefits and expenses before 6 April 2026" [7]. Employers that have never payrolled benefits will move straight into the mandatory regime, which means collecting car list prices, emissions, fuel arrangements and medical premiums in the payroll system before April 2027 [22].
Salary sacrifice cars are a common blind spot. HMRC requires a car provided through salary sacrifice to be reported [23], and its guidance notes that "exemptions on benefits in kind do not apply to salary sacrifice schemes" [24]. The Moonworkers guide to the salary sacrifice electric car explains how those benefits are valued and reported.
Building the deadlines into the payroll workflow
A reliable year-end process works backwards from 6 July. Benefit data is gathered in April and May, cash equivalents are calculated and checked against the company car calculator for cars [22], PSA items are separated before 5 July [12], and the P11D(b) is filed with time to spare before the monthly penalty begins [1].
Moonworkers' UK payroll software for SMEs holds benefit data alongside pay, calculates Class 1A at 15% and is built for payrolling benefits through the FPS, which is where the reporting is heading. Accountants managing year-end for several clients can track P11D status per employer from the accountant payroll platform, while software teams can add benefit reporting to their own products through the HMRC-recognised payroll API.
For the detail of what goes in each box, the Moonworkers guide to the P11D form covers the sections line by line, and the explainer on benefit in kind tax sets out how each benefit is valued. The timetable for the transition is covered in the guide to mandatory payrolling of benefits.
Conclusion
The P11D calendar is short but unforgiving. Filing, the employee's copy and the Class 1A declaration all land on 6 July, payment follows on 22 July with an earlier date for cheques and weekends, and the PSA runs on its own track to October. The penalties scale with headcount and part months count as whole months, so the cost of a late return is set by the size of the workforce rather than the size of the benefits bill.
The bigger shift is structural. From 6 April 2027, the benefits that generate most P11Ds begin to move into real-time reporting, and Class 1A follows them into the FPS. Employers that treat the remaining P11D cycles as a chance to clean up their benefit data will find the move to payrolled benefits a change of timing rather than a change of process.
Frequently asked questions
What happens if the P11D deadline falls on a weekend?
The 6 July filing deadline does not move. For Class 1A payments due on 22 July, if the date falls on a weekend or bank holiday the payment must reach HMRC on the last working day before it, unless the employer pays by Faster Payments.
Is a P11D(b) needed if all benefits are payrolled?
Yes. An employer that payrolls benefits does not need P11D forms for those benefits, but it must still calculate the Class 1A National Insurance due and submit form P11D(b) by 6 July.
How much is the penalty for a late P11D?
The penalty for a late P11D(b) is £100 per 50 employees for each month or part month it is late. Separate penalties and interest apply if the Class 1A National Insurance is paid late, starting with a 5% penalty once the payment is 30 days overdue.
Can P11D forms still be filed on paper?
Only in limited cases. HMRC accepts paper P11D and P11D(b) forms only from employers that have stopped trading. Employers with fewer than 500 employees file through PAYE Online, and larger employers file through payroll software.
