There are a few possibilities, perhaps the property has never had a BT type service , perhaps the previous occupant, for reasons known only to themselves , removed the socket and associated wiring , or perhaps it’s there , just you haven’t found it yet.
If the area is serviced by overhead means, you could check where the wire from the pole hits the property and trace the wiring from there into the property , if it’s served by underground cable, and is of the same style and design as neighbouring property’s then you could possibly ask a neighbour where their master socket is located .
If service is ordered , and system records show that the property had service previously, then advising to connect the equipment to the master socket on the appropriate date , and it should work , is standard procedure, even if you point out the master socket is ‘missing’ , chances are the order will proceed this way.
If the service doesn’t work , either by not locating the socket ( because someone removed it ) or you find the socket , but it doesn’t work on the day anyway, then either it gets noticed and rectified automatically by testing the line and ‘seeing’ it’s faulty, (an early life failure) or it’s reported as a fault by the person who’s name the service is in .
