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HMRC internal manual

National Insurance Manual

NIM02250 - Class 1 NICs : Earnings of employees and office holders : National Insurance benefits

If an employee continues to be paid their normal pay during periods of sickness or maternity leave and any NI benefit received has to be handed over to the employer, Class 1 NICs are payable on the earnings less the amount of the benefit.

The employer must keep sufficient details in the pay records to work out the gross earnings for NIC purposes.