Why does NES need a copy of my payslip?

NES requires a copy of your payslip as this is used to assign your pay scale and banding and confirmation of your Increment date.   E-payslips do not have your incremental date so if you provide one of these, you will be asked to provide alternative proof of incremental date. The payslip is not used to determine your tax code as this is identified separately using your P45 from your previous employer.