P11D(b)

Form P11D(b) is the employer-level companion to P11D. Where each P11D reports the value of benefits in kind given to one employee, P11D(b) is a single declaration covering the whole workforce, summarising the total Class 1A NIC the employer owes on those benefits. P11D and P11D(b) are filed together by 6 July following the end of the tax year, and Class 1A NIC is paid by 22 July (electronically) or 19 July (cheque).

From April 2026, payrolling of benefits in kind becomes mandatory for most benefits, meaning the income-tax element is collected through PAYE in real time and reported on the FPS. P11D(b) survives that change because Class 1A NIC is still settled annually rather than per pay period — so even fully payrolled employers continue to file P11D(b) summarising the Class 1A liability.

Worked example: Westwood Ltd provides company cars and private medical insurance to 25 employees. The total cash equivalent for the year is £180,000. The Class 1A NIC at 15% (the 2026/27 rate) is £27,000. Westwood files one P11D(b) declaring £180,000 of benefits and £27,000 of Class 1A NIC, and either files 25 P11Ds (legacy approach) or reports the benefits in real time through payroll (post-April 2026 default) and files only the P11D(b). Late filing attracts £100 per 50 employees per month, and incorrect figures attract penalties of up to 100% of the lost tax.