They will be his employer!
Thank you both so much! Sorry I kept throwing around 'sponsor' so much. That's what they call the companies he works for, haha. It makes sense for the unbrella company to be his employer, so I'm glad we figured that out
Also, he's concerned bc he is not on a salary. He works random railway jobs, sometimes for a couple months at a time or a week at a time, etc. It all depends on what is needed. So his employer will not be able to write his salary. How do we handle that?