What is the P11D deadline and when must I pay Class 1A National Insurance?

The P11D form reports employee benefits and expenses to HMRC. For the 2025/26 tax year, the filing deadline passed on the 6th of July 2026. However, the Class 1A National Insurance payment deadline is on the 22nd of July 2026 (or the 19th of July if paying by post). If you’ve reported benefits, that payment is urgent, so make sure you act now.

What is a P11D form?

A P11D form reports the value of benefits and expenses provided to employees that weren’t processed through PAYE. Common examples include company cars, private medical insurance, and gym memberships. Any benefit with a taxable value must be declared on the P11D unless it’s exempt or has been payrolled. HMRC uses the P11D to ensure employees are taxed correctly on the full value of their remuneration package, not just salary.

If you provide company cars, offer health insurance, or give staff vouchers or gifts, you’ll likely need to file a P11D. The form is submitted electronically to HMRC using RTI after the tax year end.

When is the P11D filing deadline?

The P11D and P11D(b) must be submitted to HMRC by the 6th of July following the end of the tax year. For the 2025/26 tax year (which ended on the 5th of April 2026), the deadline was the 6th of July 2026. If you haven’t filed by now, contact HMRC immediately as late filing attracts penalties starting at £100 per 50 employees, rising to £300 per 50 if more than 3 months late.

HMRC will accept P11D submissions only for the current and previous tax years. For further information on P11D submission deadline, check out our blog, deadline reminder: Submit P11Ds by 6th of July.

When must I pay Class 1A National Insurance and why is it urgent now?

Class 1A NIC payment deadline is the 22nd of July 2026 (or 19th July if paying by post). That’s 1 week away.

Many practice owners focus on the filing deadline and overlook the payment deadline. That’s a costly mistake. Your P11D(b) tells you exactly how much Class 1A NIC is due, so make sure you process that payment immediately.

What payment details and reference should I use for Class 1A National Insurance?

Pay Class 1A NIC directly to HMRC using your online banking. Use one of these bank accounts:

• HMRC Cumbernauld (preferred): Sort code 08-32-10, Account 12001039

• HMRC Shipley (alternative): Sort code 08-32-10, Account 12001020

Also, make sure to use the correct payment reference. Your reference must be your 13-character Accounts Office reference plus ’26’ at the end (for the 2025-26 tax year). If your Accounts Office reference is 123PA45678910, your payment reference is 123PA4567891026.

How does BrightPay simplify P11D reporting and payment?

Bright’s cloud payroll software, BrightPay, eliminates the guesswork when it comes to P11Ds. In the Expenses and Benefits section, you enter all benefits as you process payroll. At year end, BrightPay generates your P11D form and P11D(b) return automatically, calculating the Class 1A National Insurance liability. You then submit electronically to HMRC directly from the software in a few clicks.

The software also guides you through the payment process, confirming the amount due. If you’re managing multiple employees with varied benefits, BrightPay ensures nothing is missed. With the payment deadline just days away, having a system that’s already calculated your exact liability removes the last-minute panic.

For further information, check out our support articles on P11D and P11D (b) end of year returns and paying HMRC for P11D(b) – Class 1A National Insurance.

Ready to tackle year-end compliance? BrightPay Cloud handles P11D generation, P11D(b) submission, and Class 1A calculations in one place.

This content may have been developed with the assistance of AI tools. Content is reviewed by a member of the Bright team before publication. Guidance on legislation can be obtained from your industry body.