Julian more nuance. NI not due if under 21 Category M. So the young (16-20) are the cheaper option. Above 21 different story. After 5k employers NI kicks in at 15% plus 3% pension contribution. So £28600 to hire someone at 25k a year. You haven't bought their kit or trained them yet. Why have a payroll tax at all seems a reasonable question to ask? Unfortunately we have historically linked NI to benefits & state pension (Liberals 1911). Tax Reform is desperately needed.