I thought it might be worth mentioning, as I haven't had this type of call before. Phone rang. Synthesised voice said my name and then said this is BT. Your broadband will be terminated tonight. Press 1 to do something, press 2 to do something else ( can't remember what the options were).
I hung up. 1471 said "we do not have the caller's identity".
The voice was clear with a faint hint of Dalek. Much easier to understand than most foreign scammers.
I wonder what would have happened if I had pressed 1.