What Happens to Alarm Lines and Lift Phones After the PSTN Switch-Off?
Any intruder alarm, fire alarm signalling path, telecare pendant or lift emergency phone that dials out over an analogue phone line stops working when the PSTN is retired on 31 January 2027. They need testing on a digital line, an adaptor, or replacement before then.
Written by Nathan Hill-Haimes, Co-Founder, AMVIA
Quick answer
Any intruder alarm, fire alarm signalling path, telecare pendant or lift emergency phone that dials out over an analogue phone line stops working when the PSTN is retired on 31 January 2027. Government guidance says to check every connected device now, because your phone provider cannot see what is plugged into the line - the audit is on you. AMVIA audits alarm and lift lines as part of every migration.
Key Points
What you need to know.
The Deadline Is Real
BT retires the analogue network on 31 January 2027 (Ofcom). Business lines do not get the consumer safety net, so they must move first.
Your Provider Cannot See Your Alarms
Official guidance is blunt: providers will not know which devices are connected to their network. Nobody warns you per device - you have to audit.
Power Cuts Change
Digital lines die with the power unless backed up. Ofcom requires providers to offer at-risk users a solution giving at least one hour of emergency-calls access in an outage.
Lift Phones Are Named
Openreach explicitly lists lift phones, door entry systems, telecare and health monitoring equipment among devices to check before migration.
Device Lines: Analogue Today vs Digital Replacement
| Feature | On the PSTN today | After migration |
|---|---|---|
| Intruder alarm signalling | Dials monitoring centre over the voice line | Digital-certified dialler, IP or 4G signalling - maintainer confirms in writing |
| Lift emergency phone | Analogue autodialler in the lift car | Tested on digital line or replaced with GSM/4G unit; battery back-up sized to risk |
| Telecare pendant | Analogue base unit on the landline | Provider informed BEFORE switch; engineer-tested migration with safeguards |
| Power-cut behaviour | Line powered from the exchange | Dies with local power unless battery-backed; Ofcom minimum is one hour for emergency access |
The lines nobody thinks about are the ones that matter most here. Phones get migrated because people notice phones. The analogue line feeding a dialler in a riser cupboard, a lift autodialler, or a warden-call unit gets forgotten until the day it goes quiet - and these are precisely the devices official guidance singles out. Government business guidance names fire alarms, lift systems, door entry, intercoms, security alarms and telecare among the categories that rely on legacy networks, and Openreach's own checklist adds health pendants and lift phones in terms.
Why these devices break
Analogue alarm and lift equipment signals over the voice line using tones and line voltage that the PSTN guaranteed. A digital (VoIP) line reproduces speech well, but it does not guarantee the signalling behaviour a 1990s dialler expects, so a device can appear connected and still fail to raise its monitoring centre. That is why the official transition guidance tells anyone with alarm systems or telecare devices on a phone line to take steps to ensure they will continue to function, and to speak to both the line provider and the equipment provider. The scale is not small: the government's Telecare National Action Plan (February 2025) estimates 2 million people in the UK use telecare services.
The power-cut problem
An analogue line was powered from the exchange, so an alarm could dial out during a blackout. A digital line dies with your power unless something keeps the router and the device alive. Ofcom requires providers to have at least one solution that keeps emergency-call access working for a minimum of one hour in a power cut, free for customers who depend on the landline - but one hour is a floor, not a fire-safety design. For alarm receiving paths and lift lines, specify battery back-up sized for the risk, not the regulatory minimum.
What to do, in order
First, walk the estate and list every line that is not a desk phone: alarm panels, lift cars, plant rooms, barriers, door entry. Second, ask each equipment maintainer one question in writing: is this unit certified to signal over a digital line, and if not, what replaces it? Third, migrate the voice lines to VoIP and the broadband-only lines to SOGEA, keeping the numbers. The order matters - test the special lines BEFORE the analogue line is ceased, because after cessation there is nothing to fall back to. Stop sell has already been in force since September 2023, so a failed analogue line often cannot be reordered even today.
AMVIA runs this as a single piece of work: line audit, maintainer letters, migration and porting, with the alarm and lift lines tested live before anything analogue is switched off.
Frequently Asked Questions
Not necessarily. If the alarm signals to a monitoring centre over an analogue phone line, official guidance says to check it with your alarm maintainer and line provider now - analogue diallers can fail silently on digital lines even when a dial tone is present. Ask the maintainer in writing whether the unit is certified for digital lines.
Lift phones are explicitly on Openreach's list of devices to check before migration. A lift autodialler on an analogue line must be tested on the replacement digital line or upgraded (many maintainers fit GSM/4G units instead). Because a lift line is a safety-of-life line, test before the analogue line is ceased and specify battery back-up beyond Ofcom's one-hour minimum.
They can. An estimated 2 million people in the UK use telecare (government Telecare National Action Plan, 2025), and the official advice is to tell your phone provider you have a telecare device BEFORE any switch, so the migration is handled with safeguards - including engineer testing and free battery back-up for vulnerable users under the industry checklist agreed in 2024.
Only if the router and device have battery back-up. Ofcom requires providers to offer at least one solution keeping emergency access alive for a minimum of one hour in an outage, free to landline-dependent customers. For alarm signalling, treat one hour as the floor and size the back-up to the risk.
You are. Government guidance states plainly that communications providers will not know which devices are connected to their network. The line provider migrates the line; whether the alarm, lift phone or telecare unit on it survives is down to the equipment owner - which is why an estate-wide line audit is step one.
Related Resources
PSTN Switch-Off 2027
The full guide: what is changing, who is affected, and how to migrate without disruption.
SOGEA Broadband
The like-for-like replacement for a phone-line-based broadband connection - no PSTN required.
Business VoIP
Hosted VoIP from GBP5.95 per user per month with number porting handled for you.
PSTN Switch-Off Statistics
The verified countdown numbers with named sources and dates.