The term 'personal service company' is not defined in law. It is understood generally to mean a limited company, the sole or main shareholder of which is also its director, who, instead of working directly for clients, or taking up employment with other businesses, operates through his company. The company contracts with clients, either directly or through an agency, to supply the services of its director. There are many reasons for the use of personal service companies, including the possibility of reducing tax and national insurance bills. The Government's anti-avoidance legislation, often referred to as IR35, is complex and raises its own problems. The report is not intended to be a comprehensive reference work; instead it focuses on five main areas: (1) The use of personal service companies, relevant legislation and recent trends; (2) the continuing viability of the IR35 legislation; (3) HMRC's administration and the effect of recent reforms; (4) implications for the lower-paid; (5) the public sector. The Committee point to the absence of reliable information collected by HMRC. This could be rectified by amending the personal tax return and employer year end declaration and making the questions on service companies compulsory, rather than optional. HMRC failed to demonstrate that they had a sound basis for the £550m of tax and national insurance that they cited as being at risk if IR35 were to be abolished or suspended. Low-paid workers may not be aware that employment by these companies means they have fewer employment rights.