In a nutshell, IR35 came into effect in April 2000 and was designed to tax "disguised employment" at a rate similar to permanent employees. In this context a "disguised employee" refers to a worker who receives payments from a client via an intermediary and whose relationship with their client is such that had they been paid directly they would be an employee of the client and taxed accordingly.
IR35 was introduced to help distinguish between permanent employees and genuine temps/contractors. A contractor who is deemed outside the IR35 legislation can make substantial tax savings as the contractor can earn dividends (which are not subject to National Insurance Contributions).
Even though most contractors will sign an IR35 contract when they accept temp roles through recruitment agencies, these contracts are not always enough to safeguard contractors against IR35. As IR35 is a complex piece of employment law legislation we do advice clients to engage the service of a professional to help them understand their position better with regards to this legislation.
Qdos Consulting offer a well priced one-off review service and they also offer a range of insurance products for contractors.
Please have a look at their website for more information.
Also, for more guidance on IR35 you can visit