Short answer: If your intruder or fire alarm dials out over a traditional phone line, it will lose that path when the line is switched off by January 2027. The fix is usually to upgrade the alarm's communicator to IP or 4G signalling, which your alarm provider can do while the panel and sensors stay in place. This is part of the wider PSTN and ISDN switch off.
Why alarms are affected
Many intruder and fire alarm panels send their signals to a monitoring centre over an analogue phone line, or over legacy services such as Redcare. When the copper phone network is decommissioned, that signalling path disappears. The alarm may still make a noise locally, but the monitored connection that summons a keyholder or the fire service can be lost.
What stops working
- Intruder alarms that dial a monitoring centre over PSTN
- Fire alarm diallers connected to an analogue line
- Redcare and similar copper-based alarm signalling
- Any panel using a phone line as its only communication path
What to do
The good news is that in most cases the alarm panel and sensors stay exactly as they are. Only the communication module changes:
- Upgrade the communicator to IP or 4G, often dual-path for resilience, so a single failure does not leave the site unmonitored.
- Speak to your alarm monitoring company to arrange the module swap and confirm the monitoring centre supports the new path.
- Test end to end so a real signal reaches the monitoring centre before the old line is removed.
Safety and compliance: fire alarm and life-safety signalling carries insurance and regulatory obligations. Confirm any change with your fire alarm maintainer and insurer, and allow time to test. Do not leave safety-critical signalling to the last minute.
Frequently asked questions
Will my intruder alarm stop working after the PSTN switch off?
If it signals to a monitoring centre over a traditional phone line, it will lose that path when the line is switched off by January 2027. Most modern panels can move to IP or 4G signalling by swapping the communicator module. Contact your alarm monitoring company or ask us to check.
Does the fire alarm dialler need replacing before 2027?
Yes, if it dials out over an analogue line. Fire alarm signalling has safety and insurance implications, so it must be migrated to a compliant IP or 4G path with time to test. Confirm the change with your fire alarm maintainer and insurer.
What replaces Redcare and phone-line alarm signalling?
Signalling moves to IP or roaming 4G paths, often dual-path for resilience. Your alarm provider upgrades the communicator module while the panel and sensors stay in place.
Not sure if your alarm is on a phone line?
Tell us what alarm and monitoring you have and we will tell you what needs to change before the switch off, and what can stay. Read the full ISDN and PSTN switch off guide or book a readiness check.