An essential element of an employment is that the worker
provides personal service. If the worker undertakes to perform a
task and is free to hire someone else to do it or to give
substantial help, it is unlikely that the worker is an employee.
This is a very important factor to take into account in any status
It is the right to provide a substitute that is important, not whether that right is exercised. Make sure that the worker has a real choice over who does the work and that the substitute is answerable to and paid by the worker. The fact that an engager can limit the choice of substitute to a suitable person does not necessarily mean that there is no real right. However, if the engager has an unlimited right to veto substitutes then this may mean that the reality is the worker has to provide the services personally and the right of substitution is not genuine. You will need to consider such cases critically.
The information you will need to check whether there is a genuine right to use a substitute is likely to include:
It is important to bear in mind that an obligation on the worker to provide a personal service, or a condition that the worker cannot use a substitute, does not necessarily mean that that person is an employee.