BT aims to move its UK customers to IP telephony by 2025. From a report: BT is shutting its traditional telephone network in the UK, according to an email seen by The Register. The public switched telephone network (PSTN) closure is part of the company's plans to move in a fibre network direction in terms of its infrastructure. All phonecalls will eventually be made over broadband using VoIP systems, which means the company's existing wholesale line rental products, which are reliant on the PSTN, will need to be removed. BT Openreach runs the network used by all but one of the telecoms providers in the UK.