These contracts enable people to make their own arrangements to pay tax and national insurance, which could allow them to contribute less than employees on pay-as-you-earn tax (PAYE).
These forms became popular with independent contractors and were used as a way of earning high net returns (up to 85% of gross) compared to PAYE, with little corporate responsibilities.
The project focussed purely on primary legislation but special dispensation was given to the re-writing of the regulations governing PAYE by the project.