What BT Digital Voice Means for Existing Customers

Why Existing Customers Are Being Moved

Households that have had the same home phone for years are now being contacted about a change they did not request. The reason lies with the network rather than the tariff. The analogue Public Switched Telephone Network, or PSTN, that has carried landline calls for generations is being switched off, and Openreach is moving every line onto an internet protocol platform in a programme known as the all-IP migration. BT delivers this to consumers under the Digital Voice brand, and the migration follows the timeline Openreach has published for completion in 2027. The underlying copper exchanges and the analogue equipment that drives them are reaching the end of their serviceable life, and parts and expertise for that ageing technology are increasingly scarce, which is the practical driver behind a change that no individual customer asked for.

For an existing customer the change is best understood as a change of technology, not of supplier or number. The same household phone number is normally kept, calls are made and received in the same way, and the service continues to be billed by the same provider. What changes is how the call travels and where the telephone connects, which has knock-on effects for equipment and for what happens during a power cut. The voice signal that once travelled as an analogue waveform along a copper pair is now converted into digital data and carried over the broadband connection, which is why the practical differences cluster around the router and its power supply rather than around the call experience itself.

What BT Is Doing to Migrate Customers

BT is migrating customers in planned phases rather than moving everyone at once. The rollout is organised by area, with notice given ahead of the move so households can prepare. Customers who already take broadband from BT are generally moved by reconfiguring the existing service, so the phone is reconnected to the router. Customers who only have a phone line, with no broadband, are a special case: they still need a connection capable of carrying the IP service, and BT provides a suitable solution as part of the migration so that a voice-only household is not left without a working line. This staged, area-by-area approach lets the provider manage volumes, give targeted notice and resolve local issues before moving the next group, rather than risking a single mass switch.

BT identifies customers who may need additional help before moving them, and contacts them separately where appropriate. The aim is to resolve any telecare, alarm or resilience questions before the line is switched so that a vulnerable household is never caught out by the change. Where a customer has additional needs, the migration of their specific line can be handled with extra care rather than as part of a bulk area move. This careful sequencing reflects Ofcom's expectation that providers treat the switch as more than a technical exercise, paying particular attention to people who depend on the landline for telecare or who have no mobile signal at home to fall back on.

What Existing Customers Need to Do

The practical steps for most households are modest. The first is to make sure BT holds current contact details so migration notices are received. The second is to look at everything plugged into the existing line beyond the telephone, because the analogue socket may currently feed a personal alarm, a monitored burglar alarm, a care-line pendant or other equipment that was designed for the old network. The third is to flag any vulnerability, lack of mobile coverage or reliance on the landline, so the right resilience support is arranged. Devices such as telecare pendants and monitored alarms often dial out automatically over the line, so confirming with the alarm provider that the equipment will continue to work over an IP service is a sensible precaution before the switch.

When the line is migrated, the main physical task at home is usually to move the telephone cable from the wall master socket to the telephone port on the router. Where the property has extension sockets wired from the old master socket, those internal extensions are not automatically served by the router, so a cordless phone with several handsets is a common way to keep coverage across rooms. The table below summarises the steps in order. Households that have grown used to a phone in the kitchen, the hall and a bedroom should think ahead about this, because the single router port replaces the old wiring that fed every extension from the master socket.

Router and Battery Backup

Because Digital Voice carries the call over broadband, the telephone now depends on the router being powered. A customer who already has a BT router that supports the telephone port may not need new hardware, while others are provided with compatible equipment as part of the migration. The important difference from the old copper line is that the analogue line drew power from the exchange and kept working in a domestic power cut, whereas an IP line goes down when the router loses power unless a backup is in place. This single change in how the line is powered is the most consequential practical difference for many households, because it removes a property the old phone quietly relied on for decades.

This is where battery backup matters. Ofcom expects providers to offer at-risk customers a solution that delivers at least one hour of access to emergency services during a power failure, and in practice this is commonly a battery unit that keeps the router and phone running, or an alternative device where appropriate. Customers who are not classed as vulnerable are still advised to keep a charged mobile to hand as a fallback, since the resilience characteristics of the line have genuinely changed. The one-hour figure is a regulatory minimum aimed at the people most at risk, not a statement that the line will work indefinitely, so anyone in an area prone to long outages should think about how they would call for help if both mains power and the router were down for an extended period.

Support for Vulnerable Customers

BT operates additional support for customers who depend on their landline or who would be at risk if the phone failed. Identifying these customers before the move is a central part of the migration, and they may be contacted directly so that resilience and telecare can be arranged ahead of the switch. The protections flow from Ofcom's expectations that providers take particular care of customers who, for example, have no mobile signal at home or rely on a telecare alarm connected to the line. The regulator has been explicit that providers should not migrate such customers until they are satisfied the right protections are in place, which is why these lines are often handled outside the standard area rollout.

Practical support can include providing a battery backup unit, arranging an alternative resilience device, and giving extra help on the day the line moves. Anyone who is uncertain whether they qualify, or who looks after a relative who relies on the landline, should raise it with BT directly, because the additional support is triggered by the customer's circumstances rather than applied automatically to every line. A family member or carer can often flag the situation on someone's behalf, which is useful where the person at risk may not recognise that the change affects them or may not be confident dealing with the provider alone.

What Happens to Telecare and Alarms

Beyond the phone itself, the line frequently carries equipment that dials out automatically, such as a personal care alarm, a fall pendant base unit or a monitored intruder alarm. This equipment was designed for the analogue network, and some older units may not behave the same way once the line runs over IP, particularly where they rely on signalling tones the digital service handles differently. The safest course is to identify every such device during the equipment audit and check directly with whoever supplies or monitors it that it remains compatible after the switch.

For telecare in particular, the switch-off has prompted close attention from the regulator and from the bodies that oversee assistive technology, because a care alarm that silently fails would put a vulnerable person at serious risk. Standards for the reliability of such equipment, including those for alarm communications, sit behind the assurance work that providers and telecare operators carry out. Households should not assume an old alarm will simply keep working: confirming compatibility, and arranging a replacement or upgrade where needed, is the step that protects the person who depends on it.

Frequently Asked Questions

When will BT move me to Digital Voice?

BT migrates existing customers in planned phases organised by area, with notice given ahead of each move, and the whole programme follows Openreach's published timeline for completion in 2027. New orders and house moves tend to be handled earlier. Customers with additional needs may be contacted separately so their line can be moved with extra care once the right protections are in place.

Do I need a new router for BT Digital Voice?

A customer who already has a BT router with a telephone port may not need new hardware, while others are supplied with compatible equipment as part of the migration. The key change is that the phone plugs into the router rather than the wall socket. The router must remain powered for the line to work, which is why battery backup matters for at-risk customers.

What support does BT offer vulnerable customers?

BT identifies customers who depend on their landline and can provide additional help, including battery backup so the line can reach emergency services during a power cut. This follows Ofcom's expectation that providers protect at-risk customers for at least one hour in a power failure. Anyone unsure whether they qualify, or who cares for someone who relies on the landline, should raise it with BT directly.

Will my phone number change when I go to Digital Voice?

The existing telephone number is normally retained when a line moves from the analogue network to Digital Voice. The migration changes the technology that carries the call, not the number itself. Calls continue to be made and received in the same way, so contacts do not need to be told a new number.

Does BT Digital Voice require broadband?

Digital Voice carries calls over a broadband connection, so a suitable connection is needed for the service to work. Customers who only have a phone line are still catered for, because BT provides a connection capable of carrying the IP service as part of the migration. This ensures a voice-only household is not left without a working line after the switch.