As a Contractor you can handle your income in 3 different ways. Go on an agency payroll – the simplest option but you will pay PAYE and NI on your earnings; use an Umbrella Company where you again pay PAYE and NI plus pay the Umbrella Company a fee and possibly not get tax relief on expenses; or you can have a Limited Company – a little more responsibility but assuming you pass IR35, you will definitely be better off.