Many self employed people adhere to contracts that are basically crap.
If you work for an entity, that state you are self employed, and you provide a service to that company, does not mean they can treat you like dirt.
Many self employed contracts are a simple form cantract, this means the company you work for bully you, and dictate how you work. If you supply a service to a company and they impose too many conditions, they could be guilty of placing themselves in a "position of control".
For example, if you work for a company, that tells you what times you work from, make you sign in and out, make you buy your own saftey equipment, and do not give you a saftey induction, plus try to make you do extra work than your contract stated without extra pay.,
then they have a position of control, and you are a worker intitled to Core rights.
core rights means you are entitled to most basic employment rights.