Ask the provider how calls will work after the change, how to retain a number, and what happens during a power cut. If you use a care alarm or other line-connected device, involve both the phone provider and the device supplier before migration.
Start with our London fibre broadband overview to see how availability, networks and speeds fit together.
Clarify the service you are keeping
A broadband package may include a telephone service, offer one as an extra or provide internet only. Ask whether incoming and outgoing calls are included, what calls cost and whether the existing number can be transferred.
Do not cancel an old telephone service before the providers have confirmed the intended transfer process. Keep the number and account details accurate, and ask for the sequence of events in writing if the broadband and phone are moving separately.
Understand the equipment change
Ofcom explains that a digital landline uses a broadband connection and may connect through the router instead of the old wall socket. Some customers need an adapter, router or handset, which the provider should explain.
Follow the provider's equipment instructions rather than plugging devices in by trial and error. Check the actual telephone you will use after the change, including making and receiving an ordinary call.
Plan for a power cut
Digital phone equipment at home needs power. Ofcom says customers who depend on a landline and do not have a usable mobile alternative should tell their provider; an appropriate free backup solution must be offered for access to emergency services, with at least one hour of backup.
Ask what equipment the proposed backup supports, how it is maintained and how you will know it is ready. Do not assume that powering only one box keeps the whole broadband and telephone path working.
Check alarms and other connected devices first
Ofcom advises people with care alarms, health pendants, security alarms or other telephone-line devices to contact the relevant providers before a digital change. Compatibility should be checked by the organisations responsible for the equipment and service.
Make a list of devices and the supplier contacts. Ask who will confirm that the replacement arrangement works and whether any planned migration needs to wait for that confirmation. Do not rely on a successful ordinary phone call as proof that every connected device is compatible.
- Identify every device using the existing line.
- Tell both the telephone provider and the device supplier.
- Ask who is responsible for the compatibility check.
- Agree the power-cut arrangement where needed.
- Keep support contacts available offline.
Keep broadband technology and telephone service distinct
The question of fibre reaching the property is separate from the question of how voice calls are supplied. Avoid assuming that ordering FTTP automatically includes a phone plan or that keeping a landline requires buying the fastest broadband tier.
Discuss the requirement in plain terms: whether you need calls, a retained number, connected equipment or extra support. That gives the provider a clearer brief than asking for a particular technical label without explaining the use.
Review the completed setup
After the change, check the agreed number, handset and calling arrangement with the provider's guidance. Keep the equipment instructions and any backup information in an accessible place.
If something is wrong, contact the service provider promptly and explain which part has failed. This guide outlines the questions to ask; the provider and equipment supplier must confirm the safe setup for the individual household.
Your questions, answered.
Do I have to buy a phone service with full fibre?
Check the package. Some offers are broadband only, while others include or optionally add a telephone service.
Will a digital landline work if the mains power fails?
Not without an appropriate working power-backup arrangement. Tell the provider if you rely on the line and have no usable mobile alternative.
Sources & further reading
Official information behind this guide. Links checked 29 October 2026; individual datasets retain their stated reference dates.