Switching phone lines06 February 2024

Fit to Switch  public switched telephone (Image credit: AdobeStock Stephen)

The Fit to Switch industry awareness campaign has highlighted the importance of the retirement of the public switched telephone network by the end of 2025; see also http://tinyurl.com/mvbve4cb

UK phone providers agreed in December 2023 a number of new measures to protect vulnerable customers as phone lines are upgraded to the new digital network. While the government said that the transition should be straightforward for the ‘vast majority’ of consumers and businesses, it was made aware of serious incidents involving telecare users having their devices fail when trying to use them after the upgrade process.

Following a meeting convened between the technology secretary and with telecoms providers including Sky, BT, VMO2 and TalkTalk, telecoms providers have signed a charter (http://tinyurl.com/4rbe9wek) committing to concrete measures to protect vulnerable households, particularly those using personal alarms, known as telecare, which offer remote support to elderly, disabled, and vulnerable people – with many located in rural and isolated areas. Other commitments agreed include: providers will conduct additional checks on customers who have already been forcibly migrated to ensure they do not have telecare devices the provider was unaware of, and if they do, to ensure suitable support is provided. No telecare users will be migrated to digital landline services without the provider, customer, or telecare company confirming they have a compatible and functioning telecare solution in place.


As the Fit to Switch campaign makes clear, telecare is not the only function at risk. Landlines may also be used for alternative devices such as lift alarms, burglar alarms or card payment systems. Telecoms providers will not know which devices are connected to their network, and therefore it is important for business customers to review which devices they are using and determine whether they need replacing or upgrading, or whether adaptors might be required, according to the government.

The usual upgrade path is to move landline services to new digital technology using an internet connection, such as Voice over Internet Protocol (VoIP), Digital Voice or All-IP telephony.

According to business consultancy Larato, each line serving a PSTN-connected device will need to be supported by a router. Its founder Lucy Green says: “What we routinely call a router is in face a device that contains a router (that connects the device to the Internet) and a modem (that carries the signal). Also, the All-IP infrastructure doesn’t carry power, so you will need battery back-up for routers in case of power cuts.” Telecoms regulator Ofcom published guidance in 2018 for organisations that rely on PSTN lines for emergency services that requires providers to enable access to emergency organisations for a minimum of one hour in the event of a power outage in the premises, and that this solution should be offered free of charge to those who are at risk as they depend on their landline.

Larato has published a list of common services that might depend on PSTN connections to raise awareness of potentially-vulnerable devices (see box). They are more common than one might think. Green describes a familiar picture: “Imagine a single office block with a gated car park, an entry system (tap your badge to come in), a lift with an alarm, security cameras, intruder alarms, fire alarm, electric vehicle charging point, fax machines, vending machine.” That’s nine types of devices potentially at risk.

Adds Adrian Barnard of Alpha Beta Solutions: “Any local authority, health body, campus or school estate (public or private) in estate management, distributed manufacturing and logistics which have physical buildings or a facilities management requirement will have considerable needs. A local council we know with 300,000 residents expects a bill of £10m+ to replace emergency alarms, access control systems, lift phones, and replacing fixed copper connections with fibre POE [power over ethernet] and other switching for maintenance and engineering assets.”

He recommends a line-by-line review of the estate. At-risk PSTN connections might look like an old-fashioned plug socket. Many mechanical systems rely on a so-called block terminal, a small hard-wired junction box, the most commonly known of which is the BT RedCARE alarm block terminal, says Barnard. The first port of call in case of doubt is the service provider.


To support particular industries, BT Openreach [which is in charge of UK telecoms infrastructure] published specific instruction sheets about the switch-over and highlighting high-risk areas.

The alarm industry (https://www.openreach.co.uk/cpportal/content/dam/cpportal/public/images-and-documents/home/products/The-All-IP-Prog/ServiceIndustry_andBusiness/Docs/Alarm_Industry.pdf)

“Historically, the industry has relied upon analogue phone technology as a primary path. Managed services tend to use SIM technology as their primary path with the secondary path being dial up broadband. These will be affected by the move to digital phone lines.” It adds that, in particular, line cut monitoring will be affected by the loss of the 50V charge from copper lines.

The energy industry (https://www.openreach.co.uk/cpportal/content/dam/cpportal/public/images-and-documents/home/products/The-All-IP-Prog/ServiceIndustry_andBusiness/Docs/EnergyIndustry.pdf)

“Both gas and electricity companies rely on the telephone network for telemetry operations. They use over 43,000 telephone lines to monitor their services, assess network visibility, and operate circuit breakers. The lines are also used to safely monitor and control the national gas network, and for the remote management of compressors and critical control sites. The Electricity System Restoration – a vital failsafe in the event of a total or partial shutdown of the National Electricity Transmission System – also relies on the telephone network, as does the visibility and control of distributed energy resources (DERs).”

The lift industry (https://www.openreach.co.uk/cpportal/content/dam/cpportal/public/images-and-documents/home/products/The-All-IP-Prog/ServiceIndustry_andBusiness/Docs/LiftIndustry.pdf)

“In the UK every lift has an alarm, usually a button that connects to a rescue service via a preprogrammed phone number. It works by using an auto-dialler – a piece of analogue hardware that sits on top of the lift car and is plugged into the phone line using an Openreach master socket. As the industry changes to digital phone lines, everyone - the lift maintenance companies, the lift owners, and CPs [communication providers] - will have their part to play, and it’s vital that everyone knows what their responsibilities are. The division of duty must be clear: lift alarm hardware maintenance falls to the lift company, while the router and battery backup are the responsibility of the lift owner.”


“Real-time monitoring and control of water storage, treatment works, flood defence networks, and pumping and booster stations are critical to the successful operation of the industry, and currently rely on 25,000 PSTN lines to function. In remote areas, where there’s no other power source available, the remote telemetry units (RTUs) are driven solely by the power coming through the PSTN lines. While new connectivity products like Ultrafast Full Fibre broadband will be available for much of the UK, that may not be the case in remote areas – which are often the site of water industry equipment, such as pumping stations.” It says that a potential solution might be a new product, SoTAP, or single order transitional access product, that will deliver a copper

path between network terminating equipment (NTE) at customers’ premises and a main distribution or jumper frame at the exchange. However, areas will be limited.


  • Chip and pin payment machines
  • Door entry
  • Electronic tills
  • Electric vehicle charging
  • External door or entry bells
  • Fax
  • Fire alarms
  • Franking machines
  • Intruder alarms
  • Lift alarms
  • Medical equipment (e.g. caridac arrest phones)
  • Printers
  • School security devices
  • Smart meters
  • Telecare
  • Vending machine
  • CCTV
  • Operations Engineer

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