National Insurance Question

Bonuses are taxed as income so should be subject to NI

The income will be included in gross pay to be considered for NI contributions.
There is an upper limit, above which, the employee pays NI contributions at a lower rate for the pay period in question.

For Class 1 NI, employees pay 12% NI for weekly earnings between £118 and £962, then a 2% rate for earnings above this.
For Class 1 NI, employees pay 12% NI for monthly earnings between £512 and £4,164, then a 2% rate for earnings above this.

Unlike income tax, NI is not calculated on a cumulative basis, it is calculated solely based on your earnings for the pay period under consideration.

Yea angoose but as he's in 20% band then most or all of it is likely to be under 962. Depends on if he's on like 43k or 23k of course, and size of bonus of course.

Other option is if he's enough cash and company has pension, chuck it that way and save the NI on the contribtion

For that level of detail, I'd need to put my consultancy hat on and fees would be applicable
Could always take a payment in kind, such as a juicy wedge behind the bar courtesy of an understanding employer.

Joking aside, we have incomplete information, would be a good idea to have the payroll clerk run a simulation.

I hope he put the bonus on Tottenham. Nailed on so I hear