Your Landline May Not Work in a Power Cut. Here’s Why

For decades, the old landline was the one thing that kept working in a power cut. That’s changing. The UK is moving every home phone line onto digital technology, and digital phones need electricity in your home to work.

What’s changing?

The traditional analogue phone network, the copper lines that have run to UK homes for generations, is being retired. Phone companies are moving everyone onto digital landlines (sometimes called “Digital Voice”), which send calls over your broadband connection. The switch-off of the old network is due to complete by 31 January 2027.

For most people, the change is simple. You plug your phone into your router instead of the wall socket, and you keep your number.

Why power cuts matter

The old copper line was powered from the telephone exchange, so the phone kept working when your house had no electricity.

A digital landline depends on equipment inside your home, mainly your broadband router. When the power goes, the router goes off, and so does your landline. That includes calls to 999.

Who this matters for most

• Older people who rely on the landline and don’t use a mobile.
• Anyone with a telecare or personal alarm, such as a pendant alarm that calls for help.
• Homes in areas with poor mobile signal.
• Anyone with a medical condition who needs to be able to call for help.

What you can do

1. Ask your provider about a battery backup. Phone providers are expected to offer a free solution to customers who depend on their landline, such as a battery backup unit, so they can still call 999 for at least an hour in a power cut. Ask how long the battery lasts, because some last longer than others.

2. Tell your provider about telecare alarms. If you or a relative has a personal alarm, tell both the phone provider and the alarm company, so they can check it will work on a digital line.

3. Keep a charged mobile phone. A mobile with a charged power bank is your best backup. See our power bank guide.

4. Join priority registers. Many phone providers have their own priority support for vulnerable customers, as well as the energy Priority Services Register.

5. Write down important numbers. If your phone’s contacts are stored on a device that’s switched off, a paper list helps.

Mobile networks in a power cut

Mobile phone masts have some battery backup, but it doesn’t last forever in a long power cut, and coverage can drop. Keep calls short, text when you can, and have a battery or wind-up radio for local news.

Help an older relative

This is one of the most useful things you can check for an older parent or neighbour this winter:

• Do they rely on their landline?
• Has their line already been switched to digital?
• Do they have a battery backup, and a charged mobile?

More power cut basics: what actually happens in a UK power cut.