Openreach can no longer support the ageing Public Switched Telephone Network (PSTN), which means that ISDN and PSTN services are being switched off by December 2025. However, in some parts of the country, services are already being impacted. Yes, really. The services impacted are ISDN30, ISDN2, and PSTN Multi-Lines. The switching off of traditional copper telephone lines will see the withdrawal of both PSTN and ISDN telephone systems, with fibre optic-based Internet telephony taking their place. You need to be taking action now.