If a weekly paid employee does not take their holiday until some time after getting paid for it eg a member of the maintenance staff who gets their holiday pay before the firm’s annual close-down period but they remain at work and are expected to take their holiday later, the employee calculates the NICs on the pay at the time it is paid.
If the employer used these rules, NICs are due on each week’s pay separately ie for the holiday pay and the normal weekly pay.
If the employer used these rules then, for example: