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Digital phone switchover

The UK’s telephone network is changing. Essential work is underway across the telecommunications industry to switch off the old analogue network, known as the PSTN (Public Switched Telephone Network), and for all landline services to be offered digitally.

Phone lines will be upgraded to broadband lines and voice services will be provided over the top using Voice over Internet Protocol (VOIP) – this might also be called Cloud Voice, IP Voice, or Digital Voice.

Landlines aren't the only things that rely on the phone network. It also supports everything from healthcare devices, burglar alarms, and personal alarms, to home monitoring systems ATMs, card machines, traffic lights, motorway signs and railway signals. The providers of these services will need to offer them over the broadband network or other technologies such as cellular, WAN or even satellite.

Why is this happening?

The analogue phone network is fast approaching it’s end of life. It’s decades old and the aging infrastructure will soon no longer able to be maintained.

To meet these modern requirements and prevent the likelihood of increased failure rates of the legacy network, telecommunications providers are moving their customer base onto more future-proof telephone services.

The UK isn’t the first country to make this move. Estonia and the Netherlands have already switched off their analogue phone networks, and Australia, France, Germany, Japan, New Zealand and Sweden are just some of the other countries that are also in the process of winding theirs down.

Where possible, many of the new services will be run over fibre optic connections. These not only offer faster speeds but are more reliable and resilient. Voice calls will be carried over a digital line via a router – in the same way your broadband works.

When is this happening?

This is happening now, with the transition due to be completed over the next few years.

Since 2018, telecoms companies have worked collaboratively with industry, the communications regulator Ofcom, Government, and industry bodies representing security, health and critical national infrastructure who use the analogue network to prepare them for this change.

From September 2023, across the UK, Openreach (which provides services to providers including Sky, BT, Plusnet and TalkTalk) will not be offering new connections on lines that rely on copper from the exchange. This date is the national stop sell, however there are areas where full fibre build is more advanced and Openreach has already announced the stop sell of these products.

Virgin Media O2 is operating in a similar timescale and has also already begun migrating their customers onto their new network in areas where the exchanges are being decommissioned sooner.

What happens during the upgrade?

Telecommunication providers each have their own migration programmes for their business and consumer customers. The approach to migration may vary across different providers, depending on their network technology and the services they offer.

Despite these different plans, there are similarities across telecommunication providers in how migration will happen for consumer customers.

When it’s time for migration, the telecommunication provider will contact the customer in advance to make sure they have enough time to understand the changes brought about by migrating to digital voice.

For most customers the upgrade is straightforward. Some customers may have to plug their phone directly into a hub or router, and, in some instances, an engineer visit may be required.

It’s estimated that 95% of current handsets will work over the new service, however phones that are very old may not be compatible with the new technology and may need to be replaced.

Special equipment and services

There will be changes to the way some equipment works with the new technology. Some existing devices will continue to work using a digital service – provided they have the right resilience back-up in place - but others will need to be replaced. If there are devices connected to the analogue phone network (such as alarms, monitoring devices, CCTV, payment terminals or telemetry) their functioning may be impacted.

Business customers

Your phone provider will be in touch when it is time to migrate. However, early preparation is particularly important for businesses that have multiple sites and/or require multiple lines and where the phone line is being used to support non telephone equipment (for example, lift emergency systems, payment devices, CCTV).


Any business that relies on a service or product that works using a phone line needs to:

  1. Carry out an internal audit of phone line usage to ascertain what else the phone lines are being used for. It would be optimal to have a plan of migration in place as soon as possible. (See details of audit below)
  2. For any devices using the phone lines, check with the device provider whether they will be compatible with IP voice.  
  3. Ensure that any devices or solutions using phone lines have their own network and power resilience solutions as, given the changes in technology, the phone lines will no longer be powered by local exchanges. If your device or solution does not, get in touch directly with your provider.

For more complex migration cases, it would be optimal to have a plan of migration in place ahead of the Openreach national stop sell date – September 2023.

Internal Audit - checklist of things to think about:

  • Are you dependent on your landline/ Do you live in an area of poor connectivity?
  • Do you have IP ready devices
  • What devices do you currently use and will they transfer seamlessly to the router
  • Will your phone provider provide you with an ATA (analogue port) on the back of the router?
  • Who will reconnect your devices and confirm they continue to function?
  • Will you need to buy separate ATA hardware independently of your phone provider?
  • Do you have devices that rely on the current powering capabilities of the analog phone line – what is your plan for those power needs?
  • What is your plan for if there is a power outage locally?
  • Is your procurement policy taking into account the migration

Service and device suppliers

Any company that runs a service or product that works using a phone line needs to:

  1. Carry out an audit to understand whether all of their services and/ or products are compatible with IP voice and, in instances where they are not, find suitable alternatives for customers.
  2. Ensure that any devices or solutions using phones will have their network and power resilience solutions as the changes in technology means that the phone lines will no longer be powered by local exchanges and will not work in a power outage.
  3. Communicate directly with end users to ensure they understand the changes and any action they need to take.

Testing facilities for providers or suppliers of services reliant on the analogue phone line

Testing facilities are available to check the functionality of equipment on the digital phone network. Suppliers are able to test free of charge their equipment on the digital phone network to make sure it is IP compatible and to help ensure that everyone is ready to make the move.

BT has a dedicated testing facility at the research and development site in Adastral Park near Ipswich. More details can be found here: www.bt.com/about/special-services

Their team can be contacted at [email protected]


Virgin Media O2 offers a dedicated testing facility for special service providers to test their equipment’s compatibility: https://www.virginmedia.com/corporate/about-us/ip-voice-lab

Further information is available through their team at: [email protected]


Openreach has made available a test lab at their offices in Judd Street, London, where six communications providers have installed their services. To book in or learn more about what the lab can offer go here: Digital Services Test Lab (openreach.com)

The team can be contacted at:

 [email protected]

Further information on Openreach’s digital upgrade programme is available at: https://www.openreach.com/upgrading-the-UK-to-digital-phone-lines or https://www.openreach.com/upgrading-the-UK-to-digital-phone-lines/industry

Register for the newsletter at: https://www.openreach.com/wlr-withdrawal-newsletter-subscription-form

For more information please contact: 

Sarah Shepherd

Head of All-IP Industry Liaison, techUK

Sarah Shepherd heads up the recently established Digital Phone Switchover function which is housed within techUK.

The Digital Phone Switchover has been set up by Communications Providers and network operators to identify where common challenges to the IP migration program can be best resolved through a collaborative approach – be it enhanced communications and consistency of messages to increased awareness raising.

Prior to this appointment, Sarah managed the regulatory dimension of the PSTN switch off for BT plc and previously worked for the Broadband Stakeholder Group on telecoms policy issues across the broadband value chain.

Sarah has a background in European and UK policy and regulatory affairs.

[email protected]

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