A digital landline usually will not work in a power cut unless its broadband equipment has backup power. If your phone plugs into a router or adaptor, assume it depends on mains electricity until your provider confirms otherwise.
If you rely on the landline and have no working mobile or reliable mobile signal, tell the provider now. Ofcom says it must offer a free backup solution that lets you call emergency services for at least one hour. Telecare is separate: ask the phone provider and alarm provider to test your exact setup.
How can I tell whether my landline is digital?
Where does the phone cable go?
If the handset plugs into a broadband router, a small adaptor or another powered box, it is using a digital service. Ofcom says a digital landline works over broadband and many customers now plug the phone into the router rather than the old wall socket.
If a basic corded handset plugs straight into a traditional telephone socket, it may still be on an analogue line. Do not rely on appearances alone. Some installations reuse existing sockets inside the home while the service behind them has changed. Ask your provider, “Is my voice service digital, and what happens at my address in a power cut?”
| Your setup | Likely result in a power cut | What to check |
|---|---|---|
| Phone connected to a router or adaptor | Stops when powered equipment stops | Which boxes need backup and how long it lasts |
| Basic wired phone on a true analogue line | May continue while the network is available | Whether the line has already migrated |
| Cordless phone | Depends on its powered base and the line behind it | Handset and base manual, plus provider advice |
| Telecare or personal alarm | Must not be assumed to work | Alarm battery, router backup, connection and receiving centre |
The safest answer is the one for your actual line, not the phone you remember from your parents’ hallway.
Why do digital landlines stop when the electricity goes off?
What changed from the old telephone network?
The traditional analogue network could provide enough electricity down the line to power a basic wired handset during a cut. Digital calls travel through broadband equipment in the home, and that equipment normally uses mains power. The Government’s Telecare National Action Plan describes that change clearly.
The old network was not magic or failure-proof; it simply carried its own small phone power supply. A digital service needs a local backup if calls are to continue when your sockets go dead.
Will broadband work if I keep the router powered?
It may, but backup power in your home cannot guarantee that every part of the provider’s network remains available. Outages can affect one service, one provider or several networks. GOV.UK Prepare advises planning for the serious case in which mobile, landline and broadband are all unavailable.
Ask what the backup supports: voice only, or broadband and Wi-Fi too. Behaviour varies by provider, router, connection and battery unit.
What does the digital switchover mean in 2026?
Has the analogue network already been switched off?
Not everywhere. Many customers have moved, while others are still waiting. The national upgrade is broadly expected to complete during 2027. Ofcom says BT plans to retire its old Openreach network by 31 January 2027; some other companies operate their own networks and had not set equivalent retirement dates by this article’s update.
Your provider should contact you, but do not wait quietly if the line carries a care alarm, health pendant, security alarm or another connected device. Tell both the communications provider and device provider before migration. Ofcom says a telecare change can be paused until a safe arrangement is in place when necessary.
Do I have to buy a new phone?
Not always. Some customers keep their handset and phone number; others need a router, adaptor or replacement handset. The provider should explain and arrange what is required. If someone needs help installing it, or information in an accessible format, tell the provider before the change (Ofcom).
Who is entitled to free battery backup?
Is the one-hour battery for everyone?
The firm requirement is aimed at people who depend on their landline and have no other reliable way to call emergency services. If you have no working mobile, poor or no indoor mobile signal, a disability, health condition or another need that affects emergency calling, explain this plainly to the provider.
Ofcom requires a free solution lasting at least one hour for eligible customers. Some providers offer longer, but do not assume a runtime. Ask:
- Which equipment does the battery power?
- Is the quoted time standby time or call time?
- How will I know the battery is charged or failing?
- Who replaces it, and at what cost?
- How often should we test it?
Battery life varies with the model, age, condition and load. Keep the provider’s instructions with the unit and put its support number on paper.
Will telecare and personal alarms work?
Does the router battery protect the alarm too?
Not automatically. A telecare device may have its own battery, but a digital-line alarm also needs a working route to its alarm receiving centre. The Government action plan says failure can occur if the alarm battery is missing or depleted, or if the router has no backup.
The regulatory one-hour emergency-call backup is not a guarantee for telecare calls. Equipment and signalling methods vary by model. Ask the telecare provider to test the complete chain after any phone-line, router or alarm change. A test button that beeps locally has not necessarily proved that the receiving centre got the message.
What should a telecare user ask for in writing?
- Whether the alarm is analogue, digital or mobile-connected.
- Whether it has an internal battery and its tested expected runtime.
- Whether the router or adaptor also has backup.
- What happens if the mobile network or broadband service fails.
- How the receiving centre confirms a successful test.
- Who to call when a battery warning appears.
- What the household should do if the whole system is unavailable.
Do not buy a new alarm until the supplier confirms it is compatible with the digital line at the property.
What should I do before and during a power cut?
Before: make the phone plan visible
Keep a charged mobile and power bank, but remember that local mobile masts can also be affected. Put family, neighbours, GP, telecare, phone provider and electricity network numbers on paper. Keep a battery or wind-up radio for updates. Agree that a trusted person will visit someone vulnerable if calls fail (Prepare).
Test the landline backup and telecare using the providers’ agreed procedure. Do not unplug or modify supplied batteries. Record the test date and the number called.
During: try alternatives, but do not rely on one
If the landline is dead, try a mobile. Emergency calls can use another available mobile network even when your usual network has failed, but there must still be some signal. For a life-threatening emergency, call 999 or 112. If calls and internet are all unavailable, use the in-person plan you agreed rather than waiting beside a silent phone (Prepare).
Conserve phone power. Use a torch rather than the phone light, close unnecessary apps and keep the device warm and dry. Check on neighbours, especially anyone living alone or using telecare.
After: test the whole chain again
When power returns, check the router, phone and alarm rather than assuming every box recovered. Follow each provider’s instructions, confirm the battery is charging and make an agreed test call to the telecare receiving centre. Report warning lights or failed tests promptly.
People who need extra help
Tell the phone provider before migration if anyone uses telecare, has no mobile, has unreliable mobile signal, or needs installation or communication support. Also make an in-person welfare plan with a trusted neighbour, friend or relative. If powered medical equipment is involved, agree a separate outage plan with the clinical or care team. In Great Britain, the energy Priority Services Register can add notice and support for electricity cuts (Ofgem); it does not replace the phone or telecare plan.
If you live in Northern Ireland, Scotland or Wales
The phone switchover affects all four nations, but provider networks and migration dates vary, so ask your communications provider about your line. For the electricity cut itself, England, Scotland and Wales use 105. Northern Ireland uses NIE Networks on 03457 643643 and Customer Care Registers for people who depend on electricity or water for daily care (nidirect). The Government Telecare National Action Plan cited here formally applies to England; Ofcom’s consumer rules and advice cover UK communications providers.
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Sources
- Ofcom, Your landline is going digital: https://www.ofcom.org.uk/phones-and-broadband/landline-phones/future-of-landline-calls
- UK Government, Telecare National Action Plan: https://www.gov.uk/government/publications/telecare-national-action-plan-protecting-telecare-users-throughout-the-digital-phone-switchover/telecare-national-action-plan-protecting-telecare-users-through-the-digital-phone-switchover
- GOV.UK Prepare, Phone and broadband outages: https://prepare.campaign.gov.uk/be-informed-about-hazards/phone-broadband-outages/
- GOV.UK Prepare, Power cuts: https://prepare.campaign.gov.uk/be-informed-about-hazards/power-cuts/
- Ofgem, Priority Services Register: https://www.ofgem.gov.uk/your-energy-supply/how-manage-your-energy-supply/join-your-suppliers-priority-services-register
- nidirect, Care registers: https://www.nidirect.gov.uk/articles/care-registers