Referring a Friend

I have a friend (who I want to recommend) who is buying a house which has been empty for a few months. She has not got a moving in date yet but it is, hopefully, imminent. She knows the old supplier but has no idea what her usage was/will be. She would also like to have a smart meter from day one if possible.
Any suggestions/help would be appreciated

Nothing will be possible from day one. She can only make changes from the day she takes legal responsibility for the property

The only advice is the standard moving house advice. Tell the existing supplier she’s moved in and arrange payment, then begin a switch to a new supplier if desired.