What type of tradesman do I need

Joiner

Carpenter

handyman or carpenter

Any good handyman can do door handles, even if it’s like front door handles or internal door handles :)

Joiner/ Handyman - Any Handyman worth his salt should be accomplished at fitting door furniture, for a joiner it's second nature.

In my experience, handles can have various ways of fitting. Often even someone experienced will fit in the quickest possible way and not necessarily the best way. I have had to rectify many handles that have been fitted poorly. Who ever does the job, qualify how they are going to fit. If the handles have through bolts, I would recommend that. Also after installation check all for smooth operation and alignment.

I would say both carpenter or a good handyman will be able to complete this task.

It would put under handyman or joiner