Which tradesperson installs showers - plumber or electrician?

[Happydaze2]

Apologies in advance for what is likely a stupid question- been a long day, shower on the blink and I’m stressed 😩

Plumber, if electrical work is required they should be able to arrange someone to do it.

I agree, a plumber.

My guess is an electrician. To deal with electrics, the tradesperson has to be a qualified and (currently) registered electrician: l don't believe the same rules apply so strictly to plumbers unless they are messing around with central heating in which case they are classed as heating engineers instead and again, must be qualified and registered.
In some cases, you may be lucky enough to find a person who is qualified in both electrics and plumbing. Whoever you choose, do make sure their qualifications are up to date (l think they are supposed to be updated annually, but some don't bother owing to the cost of it). Very naughty imo as regulations change from time to time.

Plumber- they usually have an electrical qualification to allow them to fit a shower.

The certificate you will need on completion of the work is:BS7671 and it is issued by a (current) registered electician.

Depends whether it is an electric shower or one running off your combi boiler