PSTN switch-off: will your burglar alarm still work after January 2027?

If your burglar alarm sends its alerts down a phone line, it may stop reaching anyone when BT retires its old analogue landline network, which Ofcom says it plans to do by 31 January 2027. The siren should still sound on site, but calls to a monitoring centre, a keyholder or your mobile can fail. The fix is to move signalling onto broadband and mobile data, with a new hub or by connecting your existing wired detectors to one.

Below: how to tell if your system is affected, the UK dates that matter, and the upgrade routes using the Ajax equipment we supply.

What is being switched off, and when?

The PSTN (public switched telephone network) is the analogue copper network behind traditional landlines. Calls are moving to digital services such as BT Digital Voice, which run over broadband. Ofcom says BT plans to retire its old network by 31 January 2027.

• The government's guidance lists burglar alarms among devices that may use a landline, and tells owners to check with the supplier or manufacturer that the device will work on a digital line.
• Ofcom says to tell your phone provider before the change if a security alarm uses the line. The provider can check compatibility and may pause the move until a safe solution is in place.

Mobile networks are changing too. Ofcom says EE will start switching off 2G from May 2029, O2 from summer 2029 and Vodafone during 2030, with every operator committed to ending 2G by 2033. If your office phones are moving as well, see our VoIP phone buying guide.

Is your alarm affected?

It probably relies on the phone line if:

• a monitoring company or alarm receiving centre (ARC) is told when it goes off;
• it calls or texts you or a keyholder through a dialler wired to the phone socket;
• it used BT Redcare, which AXA reported BT would withdraw on 1 August 2025; or
• a phone cable runs from the alarm panel to the master socket.

A bells-only alarm that contacts nobody does not depend on the line. The government's guidance names fire alarms too, so check any fire panel that dials out; our Ajax wireless fire alarms signal through the same hubs. Whoever maintains your system can tell you how it reports.

What are the upgrade routes?

In each case the aim is to send alarm signals over the internet and mobile network, ideally by two independent paths so one fault cannot silence the system.

Which Ajax hub suits a phone-line replacement?

None of the Ajax hubs we list has a phone-line socket. Each signals over Ethernet and mobile data, and Hub 2 Plus adds Wi-Fi. Ajax's specifications say the channels work in parallel and the hub switches between Ethernet and SIM instantly if one drops.

Prices include VAT, delivery is extra and prices can change. Grade is the EN 50131 security grade Ajax states. Hub 2 and Hub 2 Plus also take photo-verifying MotionCam detectors; Hub (4G) does not. Compare them with our other alarm panels.

Your router needs mains power too: Ofcom notes digital landlines fail in a power cut without a battery back-up, and the router feeding the hub's Ethernet port is no different. In a cut, the hub's battery and SIM carry on. Ajax quotes up to 15 hours for Hub 2 (2G) and up to 60 hours for Superior Hub Hybrid 2.

Why does the 2G date matter?

The SIM is the path that survives a broadband fault, so its network must outlast the system. Hub 2 (2G) suits a site where reliable broadband is the main path, but its mobile path ends when 2G is retired. For a system you expect to run beyond 2029, a 4G hub keeps two working paths for longer.

Can you keep your existing wired detectors?

Often, yes. If the detectors and cabling are sound, an integration module lets them report wirelessly to an Ajax hub:

• MultiTransmitter Jeweller (£130.38) takes up to 18 wired zones (NC, NO, EOL, 2EOL or 3EOL), runs from the mains with a 12 V backup battery of up to 7 Ah, and can power the detectors.
• Transmitter Jeweller (£53.07) adds one wired device, runs on three CR123A batteries and is meant to sit inside the detector's casing.

Have old detectors tested first; more modules are in our zone expanders section.

What about monitoring, police response and insurance?

For police attendance in England, Wales and Northern Ireland the system must meet the National Police Chiefs' Council (NPCC) policy; Scotland follows Police Scotland's. NSI explains this needs a police-recognised installer, an approved ARC and a police unique reference number (URN), and that monitored systems installed since June 2019 must conform to PD 6662:2017 and BS 8243. Ajax lists PD 6662:2017 for the hubs above, and they report to an ARC using SIA DC-09 or Contact ID.

Insurers often set the signalling standard. Ahead of the Redcare withdrawal, AXA said it would accept a dual-path DP3 system certificated to BS EN 50136-1 as a like-for-like replacement, fitted by an NSI or SSAIB-regulated company with annual maintenance. Ajax lists DP3 among the transmission categories for Hub 2 (2G) and Superior Hub Hybrid 2. Check your own policy wording first.

Zenith is a supplier: we do not fit or monitor alarms. For police response or an insurer's terms you will need an NSI or SSAIB-regulated firm, and we can recommend a qualified installer depending on the job and area.

Our take

The January 2027 date is close, but the real risk is an alarm that looks fine and has quietly stopped reaching anyone. Check how yours signals now. If you are replacing, pick a hub with two independent paths and a mobile path that outlives 2G: Hub 2 (4G) is the sensible middle ground, Hub 2 Plus adds Wi-Fi, and Superior Hub Hybrid 2 suits Grade 3 sites or a wired Fibra system. Healthy wired detectors can stay, through a MultiTransmitter.

Want a second opinion? Call us on 01902 902251 or send us the details, and browse the full Ajax wireless alarm range. We ship nationally to England, Scotland and Wales.

PSTN switch-off: quick questions

Will my burglar alarm stop working after the PSTN switch-off?
The siren should still sound, but if the alarm signals over the analogue line, alerts to a monitoring centre or keyholder may not get through.

When is the PSTN switch-off?
Ofcom says BT plans to retire its old landline network by 31 January 2027.

Can I plug my old alarm into a digital phone line?
Sometimes. The government advises checking with the supplier or manufacturer, and an adaptor may be needed.

Do Ajax hubs need a landline?
No. They signal over Ethernet and mobile data, plus Wi-Fi on Hub 2 Plus.

Is a 2G hub still worth buying?
Where broadband is the main path, yes, but UK networks start retiring 2G in 2029. For a lasting mobile path, choose 4G.

Source: Ajax Systems blog, August 2023 (its 2025 date has since moved). UK sources: Ofcom, Your landline is going digital; Ofcom, 2G and 3G switch-off; GOV.UK, analogue to digital landlines; GOV.UK, guidance for local authorities; NSI, Intruder alarm systems; AXA, Redcare withdrawal. Product figures from Ajax specification sheets.