As the dominant operator in British telecommunications, BT's businesses are operated under special government regulation by the British telecoms regulator Oftel.
(Trying to work out how to record the timeline: National Telephone Company -> GPO -> The Post Office and British Telecom -> BT -> BT and mmO2... ?)
(The Post Office is now the privatised company Consignia.)
BT Group has four main businesses:
The former mobile telecommunications business of BT ("BT Cellnet") has now been demerged into a separate business named "mm02?".
External links: