What is the PSTN switch-off all about?

Last updated: 27 September 2026

The PSTN switch-off is the retirement of the UK’s old copper telephone network, the Public Switched Telephone Network. BT and Openreach are moving every landline to digital, internet-based calling. The deadline for completing the switch-off is 31 January 2027.

What does it mean for my business?

• Traditional analogue and ISDN phone lines will stop working and must be replaced with digital services such as VoIP or a cloud phone system.
• Broadband that relies on a phone line (such as ADSL or some FTTC) moves to data-only lines such as SoGEA or full fibre (FTTP).
• Other equipment that uses a phone line can be affected too, including alarms, lift emergency phones, card machines, franking machines and door entry systems. Check these with your suppliers.
• You can keep your existing phone numbers by porting them to a digital service.

What should I do now?

1. List every phone line and device connected to one.
2. Check your broadband contract and whether it depends on a phone line.
3. Plan the move to a cloud phone system or Microsoft Teams calling before your lines are switched over.

ABCOM helps businesses across Sussex move to cloud phone systems and VoIP and business broadband with minimal disruption. Talk to us about your lines.