In 2016, HMRC estimated that only 10% of PSCs (personal service companies) were applying the IR35 rules correctly, costing the exchequer £440 million in that year. To improve compliance, the government introduced reforms that shifted responsibility for making status determinations from the worker to the hiring body, which also became liable for any unpaid tax where it had failed to comply. These reforms initially applied to the public sector from April 2017 (affecting around 50,000 PSCs).
Read this post