The terminology is the prob,
under taxation rules kit is very unlikely that an apprentice could be self employed(SE)
The law has evoled some quite stringent tests to show ether someone is employed(E)or not, usually Inland revenue cases, where HMRC chase SE people who should be E but have purported to be SE.
a lot of the case law has come from cases involving the .....Financiall Services and Employment tribunals
In the Finacial Services cases, people wouls 'leave' their job with say 'Sun Life@and then re engage doing the same job with the same firm but as an independant, with all the advantages of being SE (There are cons - but that is not the subject here)
HMRC said 'ballcocks' youcant just elect to work like that, the Court tends to agree and the tests have evolved from the early 18th sentry 'Master/Servant' test , to quite in depth analysis
Basic tests now applied include, inter alia
Does anyone tell you where, how and when to do your work (Original Master/Servant test)
Do you work exclusively for one person (majority of your work)
Supply tools and materials transport etc
Hoilday pay
Sick pay
are you responsible if it all goes belly up
do you get the lions share of profit
Annual leave
etc
There are at least ten if not more headings that a court would consider. You cannot just elect to be SE, you have to be able to demonstrate that you are.
An apprentice by definition would almost certainly be employed.
Now an electricians mate could be SE, but again the same tests apply. you could go this route, qualify through time and experience etc
a bit of a waffle, but the law often is