Personal alarms for elderly parents: which ones still call for help when the power goes out?

If you’re choosing a personal alarm for a mum or dad who lives alone, the question that matters most is how it gets its call for help out of the house, because that decides whether it still works when the power goes off. On the NBN, the home phone runs through the modem, and an alarm that dials through it goes quiet in a blackout. We’re phone line and NBN technicians, so this guide stays on that side of it. If you’d like the connection at their place looked at before the alarm goes in, book a home visit that checks the connection and everything plugged into it.

What kinds of personal alarm are there?

There are three kinds, sorted by how they call for help: an alarm that dials through the home phone, an alarm that calls over the mobile network, and a watch with fall detection.

The three kinds of personal alarm, and what each one relies on

Kind	How it calls for help	What it needs to work
A base unit on the home phone	The button tells the base unit, which dials out through the phone line	Mains power, the modem and the NBN, all on at once
A 4G alarm	A base unit or a pendant with its own SIM calls over the mobile network	Mobile coverage where your parent is, and a charged battery
A watch with fall detection	The watch calls from its own mobile service, a nearby iPhone, or Wi-Fi Calling	Being worn and charged, and a mobile or internet connection

The first kind is the old design, made for the copper phone line, which drew its own power from the exchange. The second is what NBN Co says an alarm provider may suggest instead. A 4G base unit has its own SIM, so it doesn’t use the modem, and its backup battery is what lets it keep working when the power is off.

Some 4G alarms are a pendant on its own, with the SIM in the pendant and no base unit.

A watch with fall detection suits a parent who already wears one every day and keeps it charged.

A home phone alarm or a 4G alarm can be monitored, meaning a monitoring service answers the call, or unmonitored, meaning it rings a short list of family numbers you choose. That’s a separate decision, and it’s in the checklist further down. A watch with fall detection is different again: it calls emergency services.

How does each kind of alarm call for help?

Each one sends its call down a different path, and the path is what breaks, or doesn’t, when something at the house goes wrong.

Pick what happens at the house

Power on Power out Mobile network down

Power on

Home phone alarm

Calls out through the modem and the NBN.

4G alarm with its own battery

Calls out over the mobile network.

Watch with fall detection

Calls from its own mobile service, a nearby iPhone, or Wi-Fi Calling on the home internet.

Power out

Home phone alarm

Stopped. The modem has no power, so the call can't get out.

4G alarm with its own battery

NBN Co says an alarm like this, with a backup battery, can still work in a power outage.

Watch with fall detection

Can still call if the watch or a nearby iPhone has a mobile connection. The home WiFi is off.

Mobile network down

Home phone alarm

Doesn't use the mobile network, so a mobile outage doesn't stop it while the power and the NBN are on.

4G alarm with its own battery

Can't call. It has no mobile network to use.

Watch with fall detection

Can use Wi-Fi Calling over the home internet, if it's set up. With neither, it can't call.

Whatever the alarm, keep a charged mobile within reach. NBN Co recommends it for anyone with a medical condition.

An alarm that dials through the home phone

On the NBN, the home phone is no longer a copper line with its own power. It runs from a phone port on the modem, and the modem plugs into a power point. So a base unit on the home phone needs the power, the modem and the NBN all working before its call can get out. NBN Co says (opens in a new tab) some medical alarms may not be compatible with the NBN at all times, and to speak to the alarm provider or manufacturer to check.

Our technician has made the same point on the phone for years, mostly about security alarms that dial out: if the alarm depends on the modem, losing the power silences it, whether that’s a blackout or someone cutting the power on purpose. Some callers only found out when their alarm stopped working after the NBN went in.

An alarm that calls over the mobile network

A 4G alarm has its own SIM, and the kind worth having has its own backup battery as well, so it doesn’t use the modem or the NBN to call out, and the battery keeps it going for a time when the house power is off. NBN Co’s medical alarm page says a provider may suggest a new alarm with a back-up battery that connects via a mobile network, so that it can still work during a power or NBN outage. It’s the same answer our technician gives callers with an alarm on the NBN: a separate mobile dialler with its own battery is the surer way for an alarm to call out.

What it does need is mobile coverage. A 4G alarm is only as good as the signal where your parent lives, and in the room where the base unit sits. If the mobile signal at the house is poor, the options for bad mobile reception at home are worth reading before you buy.

A watch with fall detection

Apple says fall detection works on Apple Watch SE or later, Series 4 or later, and Ultra or later, and that it’s on automatically for anyone who entered an age of 55 or over. After a hard fall the watch taps the wrist, sounds an alarm and shows an alert. If the wearer stays still for about a minute, it counts down for 30 seconds, then calls emergency services and messages the emergency contacts saved in Medical ID with the location.

Two things to know before you rely on it. It calls emergency services, not the family first. And it needs a mobile connection or Wi-Fi Calling with an internet connection, from the watch or a nearby iPhone. Apple’s fall detection page (opens in a new tab) also says plainly that the watch cannot detect all falls. To check it’s on, open the Watch app on the iPhone, tap My Watch, then Emergency SOS, and look at Fall Detection. Apple offers Always on or Only on during workouts there, so check which one is picked.

If it’s the phone itself that’s the question, what to look for in a phone or tablet for a parent covers Emergency SOS, hearing aids and the simple modes.

What happens to a personal alarm in a blackout, or on the NBN?

In a blackout, in most NBN homes, an alarm that dials through the home phone stops. NBN Co says any equipment connected through the NBN will not work during a power outage, and that covers the modem the home phone runs from. A 4G alarm with a backup battery can still work, NBN Co says, and a watch can still call if it or a nearby iPhone has a mobile connection.

How much of the NBN goes down depends on the connection type. On fibre to the node, the curb, the building and HFC, NBN Co says the service won’t work if the power is out in the network itself, and backup power at home can’t bring it back then. NBN Co’s medical alarm page says Fixed Wireless and Satellite services won’t work in a power outage either. On fibre to the premises, NBN Co says the phone won’t work in a blackout unless there’s a battery backup and a corded phone correctly connected. What keeps working on the NBN in a blackout goes through it type by type, and how to tell which NBN connection your parent has shows how to read it off the boxes on the wall.

Whatever alarm your parent has, keep a charged mobile within reach: NBN Co recommends one at all times for anyone with a medical condition. The ACMA says a 000 call from a mobile is carried on any available mobile network, as long as your parent is in the coverage area of one of them.

Is the NBN medical alarm register still open?

No. NBN Co closed its Medical Alarm Register on Friday 30 June 2023, and says it is not an ongoing service, so there’s nothing to register with NBN Co now.

What NBN Co suggests instead is the same for everyone: speak to the alarm provider or manufacturer about whether the alarm works with the NBN, consider a newer alarm that connects over the mobile network with a backup battery, and test the alarm after it’s installed. If the NBN keeps dropping out at your parent’s place, an alarm that dials through it has the same problem, and that’s a job for an internet technician who tests the line and the modem. When the internet is down and the power is on, checking for an NBN outage comes first.

Is an old 3G personal alarm still OK?

No. Telstra and Optus began switching off their 3G networks from 28 October 2024, and the ACMA says TPG Telecom’s Vodafone network had already switched its 3G off. Telstra says a device that only connects to its 3G network and hasn’t been updated to 4G or 5G will no longer work, and its list of affected devices includes medical alert devices. Optus lists personal medical transmitters and medical alarms.

It isn’t only 3G. The ACMA says (opens in a new tab) the switch-off also affected some 4G devices, and that older 4G devices and devices bought overseas are most at risk. Our technician’s advice to a caller with a 3G dialler was the same: upgrade to a 4G unit. If your parent’s alarm was moved onto the mobile network years ago, ask the provider or the manufacturer whether it’s 4G. Optus says to contact the device’s manufacturer, because it doesn’t supply these devices.

What should you check before you buy a personal alarm?

Check five things: how it calls out, the batteries, who answers, what happens after a fall, and how you’ll test it. Ask the provider before you pay, and write the answers down.

• Does it work on 4G, and on whose network? Ask which mobile network its SIM uses, and check that network’s signal at the house, in the rooms your parent spends time in.
• How long do the batteries last? Ask how long the base unit keeps going with the power off, and how often the pendant or watch needs charging. Then decide who will remember to charge it.
• Who answers the call? A monitored alarm calls a monitoring service. An unmonitored one rings the family numbers you set. If it’s family, someone on the list has to be ready to answer at three in the morning.
• Is it a fall alarm, and what happens after a fall? Some alarms say they detect a fall on their own. Ask how it decides a fall has happened, whether your parent can cancel a false alarm, and who it calls. Apple’s own page says its watch can’t detect every fall, so ask any provider the same question.
• How do you test it? Ask how to test it without ringing 000, and test it again after any change to the phone, the modem or the NBN.

Also ask whether it can be worn in the shower, and whether it works in the garden or at the shops, or only near the base unit.

Can the government help with the cost?

Sometimes. The government’s Assistive Technology and Home Modifications list includes personal emergency alarm systems, and My Aged Care says whether someone is approved for that scheme is decided at an aged care assessment. So if your parent has had, or is due for, an aged care assessment, ask about an alarm there before you buy one yourself.

Priority Assistance: tell the phone provider about a medical condition

If your parent has a life-threatening medical condition, ask their phone provider about Priority Assistance. Telstra describes it (opens in a new tab) as a priority fault repair and connection service for customers who depend on a working home phone because of a life-threatening medical condition. The person, or someone living at the home, must have a diagnosed life-threatening medical condition, and Telstra asks for a medical certificate, or a statutory declaration if getting to a doctor isn’t possible. Telstra also describes a Priority Assist phone for eligible customers, with a battery and a built-in SIM that switches to a mobile service if the phone line goes down; Telstra says whether you can get one depends on the 4G signal strength at the home.

The ACMA says Telstra must provide Priority Assistance, and other providers may choose to. NBN Co adds that on fibre to the premises, a battery backup is required for Priority Assistance. If your parent is with another provider, ask what it offers. Either way, our technician’s advice on the phone is the same: mention the medical condition when you ring the provider about a fault or a connection, so it can be prioritised.

Priority Assistance is about the phone service, not the alarm. It doesn’t replace an alarm that can call out in a blackout.

When to call us, and when you don’t need to

You don’t need us to choose or buy an alarm, to set it up with the alarm provider, or to apply for Priority Assistance: those are between you, your parent and the provider. If your parent’s alarm is a 4G unit or a watch, it doesn’t touch the phone line at all.

Call us when the alarm plugs into the phone at home, or you’re not sure how it’s connected:

• The base unit is on the home phone and you want to know whether the socket it’s in actually gets dial tone from the modem. Phone line repair traces the wiring between the modem and the sockets.
• The phone socket is in the wrong place for where the modem sits now. A new phone point puts one where the alarm needs it.
• You don’t know how the phone, the modem and the NBN box are connected or powered at your parent’s place. An NBN technician can check how the phone is wired and powered, and which type of NBN it is, so you can ask the alarm provider the right questions.

If someone at home needs a phone or an alarm that works in a blackout, say so when you ring us, before anything is booked. Ring 02 9188 1577 or send us a message.