BT Digital Voice: what it means for your landline
In brief
- BT Digital Voice is BT's replacement for the old analogue landline. Your voice calls travel over your broadband connection instead of the copper line.
- BT sends a letter and then usually a follow-up call, followed by equipment (often a new Smart Hub or an adaptor) in the post.
- Your phone number stays the same. Most corded and cordless handsets still work; they plug into the router instead of the wall socket.
- BT offers a free battery backup unit to customers who rely on their landline, including anyone on the Priority Services Register.
- Scam calls pretending to be from BT are common. BT will not ask for payment during a Digital Voice upgrade call.
What is BT Digital Voice?
BT Digital Voice is BT's rollout of internet-based phone service. Instead of your call travelling over the old analogue copper network, it travels as data over your BT broadband connection. This is the same underlying change that every UK phone provider is making before the analogue network is switched off in January 2027.
From the user's point of view the main visible difference is where the phone plugs in. On the old service the phone connected to a wall socket. On Digital Voice the phone plugs into a port on the back of the BT Hub (sometimes labelled "Phone 1" or "Tel"). The dial tone is the same, 999 still works, and the number stays the same.
When will BT switch my line?
BT is migrating customers in waves. You will be contacted by letter at least four weeks before your planned switch date, followed by a reminder call. If you have not had a letter yet, you can ring BT on 0800 800 150 and ask when your area is due.
BT is prioritising simpler households first and deliberately slowing down for customers with telecare, health conditions, or who cannot work with broadband alone. If you depend on your landline, tell BT this explicitly when they call; they are required to pause and arrange a safe migration rather than push ahead.
What BT sends you and how to set it up
The typical package contains:
- A new BT Smart Hub (the broadband router) if your current hub is older than Smart Hub 2
- A small adaptor if your existing hub does not have a phone port
- A printed guide explaining which cable goes where
- A battery backup unit, if you have asked for one or if BT has identified you as needing one
Setup is usually a single cable move: take the phone lead out of the wall socket and plug it into the port on the back of the hub. You do not need an engineer visit for most homes.
Is BT Digital Voice free?
Yes. BT does not charge extra for the switch, the hardware they send, or the battery backup if you qualify. If you keep the same voice plan, your line rental and call charges do not change.
The only costs you may face are indirect: for example, if your telecare alarm is incompatible with digital voice and the alarm supplier charges to replace the base unit. See telecare and personal alarms for how to manage this.
What to ask BT when they call
- "When exactly will my line be switched?" Write the date down.
- "I have a [telecare alarm / burglar alarm / lift emergency phone / fax / payment terminal]. Will it work on Digital Voice?" If BT cannot confirm, ask them to pause until the device is tested.
- "Will you send a free battery backup unit?" Yes if you are on the Priority Services Register or depend on the landline.
- "Will my phone number move across?" Answer should be yes.
- "What happens in a power cut?" The honest answer is that the phone will not work without backup power; BT will offer a battery backup as the mitigation.
Watch out for fake BT upgrade calls
Scammers exploit the Digital Voice switch by pretending to be from BT and asking for payment, passwords, or remote access to your computer. BT will never:
- Ask you to pay for the Digital Voice upgrade itself
- Ask for your bank details or full password during a call
- Pressure you to decide immediately ("your line will be cut off tomorrow")
- Ask you to install software so they can "help"
If a call feels wrong, hang up, wait five minutes, and ring BT back on 0800 800 150. Report the call to Action Fraud on 0300 123 2040. See our scams and fake upgrade calls guide for more.
Common questions about BT Digital Voice
Will my BT landline work in a power cut?
Not without a battery backup. BT Digital Voice needs the Smart Hub to be on, which needs mains power. BT supplies a free battery backup unit that keeps the phone working for up to an hour, or longer for vulnerable customers on the Priority Services Register.
Do I have to take the BT upgrade?
Not immediately. You can ask BT to pause if you have a telecare alarm, a safety device, or a health condition that means losing the landline is risky. BT must leave you on the old service until a safe migration is arranged. You cannot stay on analogue forever, though: the whole network shuts down by January 2027.
Will my BT number stay the same?
Yes. BT keeps your existing landline number through the Digital Voice switch. No porting form, no loss of the number, no gap in service.
Can I still use my old BT corded phone?
Usually yes. Most corded and cordless BT phones plug straight into the Smart Hub's phone port and work normally. Very old rotary phones and certain niche cordless systems may not; BT's call or letter should confirm whether your specific model is compatible.