My last apprentice got a job with a fairly large local firm and after about 6 months, the company ran into problems, we'd had some really bad weather and it had affected house building, and this firm did a lot of work on new builds. Well after laying off about 15 lads for a fortnight, Christmas arrived, after Christmas they were all called into the office and told the company would no longer be keeping them on, they were only going to employ 1 spark full time. Anyone who wanted to work for them could do but would have to be self employed, the young lad came to ask me my views on this and I said he'd need to think carefully as there would be a lot of expense in going it alone. There's a van, all the insurances, test gear, maybe extra tools, you need to put money away for holidays and sickness, because you don't get holiday or sick pay working for yourself.
Anyway he went in and had a chat with them, they'd be providing a van, for free, supplying all test gear and any tools he needed outside of his normal kit, they also guaranteed him regular work, the only thing was that during any quiet spells he'd have to look after himself and wouldn't get paid holidays, also the van couldn't be used unless it was for their business. Clearly in my opinion this isn't being self employed, it's just another way of getting around paying employers NI and workers rights etc. I asked if he had enough money to buy the kit he needed to wire the houses and if he was going to be ok working out prices, "no need, they are paying me X per house and supplying all the kit" definitely doesn't sound like being SE to me.