I need information on uk nurses employment conditions

I need specific information on the admin./personnel process a UK nurse has to go through if they wish to have certain payments deducted from their pay or enter a salary sacrifice scheme. The formal process and time scale involved.

Could be easily answered by a nurse (NHS or agency). Alternatively someone willing to find out answers to my questions, which I will give them. Someone who is a UK nurse or knows UK nurses may be quicker at this. But anyone who is able to research can do it.