If I book a specific tradesman AIBU to think they shouldn't send someone else?

[Whippet]

Booked an electrician to do some work. He came round to assess and quote and I thought he was OK. His business was called his name e.g. JSmith Electrical and all his reviews were about him personally e.g. John was tidy and polite; John was thorough and explained everything etc.

There was half a day of follow up work to do which I asked him to do. I wasn't around for that, but it turns out that someone completely different came to do that.
He (John) didn't ask/tell me this in advance and I only found out because I asked a couple of questions later.

AIBU to think this isn't OK and he should have checked with me beforehand?

Depends if he employs that second person or if he just sent a mate round. If he employs the person then I don't see anything wrong with that.

Well that's the thing, I don't know, as he didn't tell me!

I chose him after checking he had specific qualifications and accreditations, but I don't know anything about this other guy.

He is listed as a 'Sole Trader' so I don't suppose his 'colleague' is employed by him.
I wonder what that would mean for insurance for example?

I think you’re being over fussy and that this is acceptable practice.

Sole traders can still employ people! Being a sole trader just means he is the sole owner of his business. I think YABU as I assume this person is his employee of course!

YABU - as above this will be his employee, this is very very normal practice

OK, so seems this is common practice.

Don't want to drip feed, but it was actually for a house that I rent out (same town). My tenant is a single mum, working from home, who understandably is cautious about having strangers in the house.

I went to meet "John"/ introduce him the first time and then she said it was fine when he needed to come back. After the different bloke (who she said she found a bit creepy) had been she called me and said she felt uncomfortable and I should have told her.

Clearly this is something I'll need to ask up front in future.

I think its not unusual at all, especially if it's just to finish off a few bits.