Sub mains supply wiring

[dodie80]

We currently have a property being split into 2 No. flats.
The local electricity board have put the 2 No. meters and consumer isolators external at ground floor level within a housing.
My question is can we run the upstairs flat sub mains supply (SWA) through the ground floor flat to the first floor flat or does this have to be external?

 

[buzzlightyear]

It could be done either way, have you spoken to your spark.