IR35, also known as the Intermediaries Legislation, was announced in an Inland Revenue press release in 1999. From the 6th of April 2000 it required engagers within the public sector to assess their off payroll workers.

From the 6th of April 2021 further changes have been announced to IR35 which will require all medium and large businesses within the private sector to assess their workers, in the case of small businesses responsibility will still rest with the worker. Read our definitive guide to learn about IR35 legislation, how to assess your off payroll workers, how to make payment to the worker in the case that IR35 applies or that it doesn't and what the penalties could be if you fail to comply.