What is changing with UK landlines

Last reviewed: 2026-03-04

The short version

The UK's copper phone network, which has carried landline calls since the early 1900s, is being switched off. The digital switching layer (the PSTN) was added in the 1980s, but the underlying copper lines go back much further. Every phone provider is moving customers to a new system where voice calls travel over broadband instead of the old copper network. Your phone number stays the same, but the technology behind it changes.

The target date for completing this is January 2027.

What is the PSTN?

PSTN stands for Public Switched Telephone Network. Strictly, it refers to the digital switching system built in the 1980s to route calls across the copper phone network. In practice, most people use "PSTN" as shorthand for the whole analogue landline system, copper wires and all. The copper network itself has been in use in the UK since the early 1900s.

The PSTN also carries other types of communication: fax, alarm signals, telecare calls, and data from devices like payment terminals. Anything that "dials out" over a phone line uses this network.

What is replacing it?

The replacement is called "digital voice", "VoIP" (Voice over Internet Protocol), or sometimes just "IP voice". Instead of sending your voice as an analogue signal over a dedicated copper pair, the new system converts your voice into data and sends it over your broadband connection, the same one you use for the internet.

From a user's perspective, you pick up the phone and dial a number just as before. The difference is that the call travels through your broadband router, not through the old analogue exchange equipment.

Why is it happening?

• The old equipment is at end of life. The exchanges that run the PSTN are decades old. Spare parts are increasingly difficult to source. Maintaining the network is becoming impractical.
• The copper network is being retired. As full-fibre broadband (FTTP) is rolled out, the copper lines that carried the old phone service are no longer needed in those areas.
• New stop-sell rules. Since September 2023, phone providers can no longer sell new analogue lines in most areas. New customers automatically get a digital voice service.

What stays the same

• Your phone number does not change
• You can still call any number (landline, mobile, 999, 101, etc.)
• You can keep using your existing phone handset in most cases (it plugs into the router instead of the wall socket)
• Call quality is typically the same or better

What changes

• Your phone connects to the router, not the wall socket. The phone cable moves from the phone socket on the wall to a phone port on the back of the broadband router.
• The phone needs the router to work. If the router loses power or broadband goes down, the landline goes down too.
• Power cuts affect the landline. On the old system, a basic corded phone could work in a power cut because the line carried its own power. On digital voice, the router needs mains power. Read more about power cuts.
• Devices that use the phone line may stop working. Telecare alarms, burglar alarm communicators, fire alarm signalling, door entry systems, fax machines, and payment terminals may not work correctly over digital voice. Check your devices.

Who is doing this?

Every UK phone provider is carrying out their own migration. The timing and process varies:

• BT: rolling out "Digital Voice" to all customers
• Sky, TalkTalk, Plusnet, EE, Vodafone and others: each running their own migration programmes
• Openreach, the network operator that maintains the physical lines for most providers, is retiring the underlying exchange equipment

You will be contacted by your phone provider before your line is migrated. If you have not been contacted yet, you can call them to ask about your timeline.

What should I do?

1. Find out what devices use your phone line. How to identify what you have.
2. Run the device risk checker. Start the checker.
3. Make a power-cut plan. Build your plan.
4. Contact your provider if you have questions or concerns. What to say when you call.