Since 6 April 2021 private sector employers, apart from small businesses as defined in The Companies Act 2006, are now responsible for deciding whether or not the contractors they use are de facto employees and therefore if PAYE and NIC deductions should be made from payments to them. However, with any new set of tax rules there are pitfalls for the unwary and engagers could be building up large tax arrears if they make mistakes. Here are the top five pitfalls to avoid when it comes to IR35: Be careful: Businesses need to be be careful when dealing with IR35 1. Not identifying all relevant contractors