I might be wrong but I don’t think you can write a ‘UK Caller ID’ posting because you have numerous carriers such as BT, NTL, Telewest etc.
I understand, because NTL bought up many smaller companies years ago there isn’t even standard technology for NTL, it depends what switch technology the company they bought was using.
This is what I was told, it may be incorrect but it sounds reasonable to my untrained ear.