Short version: one electrician, not four, and you still have one job of your own at the end.
Your answers tell us whether there is a job here at all. If the surface rules you out, we say so instead of passing it on.
It goes to a single electrician covering your postcode, with your answers attached, so the first call is not twenty questions.
Usually for an outdoor socket, sometimes for a circuit change, occasionally for an inspection of what is already there.
Where the panel is going and how far that is from the nearest suitable socket. What is on the circuit already. The age and condition of the consumer unit. And whether the total panel capacity is above 960 watts, because above that the manufacturer must advise an assessment of your existing installation.
If you have the kit already, having the model to hand helps. If you have not bought yet, that is arguably better, because the answer may change what you buy.
Telling your network operator, within 28 days of installation.
A short form carrying your name, an email address and where the device is installed. Reckon on ten minutes. Your electrician is not responsible for doing it, and in Great Britain it is simply how the connection rules are built. Northern Ireland runs on a different arrangement that nobody has settled yet.
Settle this before you plan anything bigger. The connection rules stop at a single plug-in solar device per household, so there is no second unit to add later.
It takes about a minute.