AI voice agents
How do you keep answering business calls in a power outage?
It's easy to find out how your phones behave in an outage during one, with a customer on the other end. Better to find out on a quiet afternoon. There's a test for that further down.
What stops working when the power goes
Anything that plugs into the wall. Usually that's the fibre, the phones and whatever's stored on them.
Start with the fibre. The fibre box (the ONT) and your Wi-Fi router both need electricity, and when they go down, so does any phone service that runs over that connection. Vox, a South African internet provider, sells a backup unit for exactly this.
Then the phones. IP desk phones, a PBX in the server cupboard and cordless base stations all need power at your premises. And if your "ring the cellphone when nobody answers" rule lives on a box in the office, it stops when the box does. A caller may hear nothing useful at all.
Cellphones keep going on battery, which makes yours the obvious backup line. That works until the battery runs flat, or you're on a roof, under a car or with a patient. And whether the network itself stays up through a long outage isn't in your hands. So plan for the parts that are.
Where your forwarding should live
Somewhere that doesn't depend on your building. A forwarding rule can sit in different places, and they behave very differently when the power goes:
| Where the rule lives | Does it keep working in an office outage? |
|---|---|
| On a phone system or router in your office | No. It stops with the equipment. |
| In your cloud phone provider's portal | It may, but ask your provider what happens to calls when your handsets go offline. |
| On your mobile network | Yes. The network does the forwarding, away from your premises. |
That last row is written into the standard. ETSI's technical specification for call forwarding describes forwarding that sends calls on when a subscriber "is not reachable", and gives a phone that has dropped off the network or is out of coverage as examples. So a cellphone that's switched off or flat can still pass its calls on, as long as the forward was set up beforehand.
If your published number is a VoIP or cloud line, forwarding is usually a setting in the provider's portal, not on your desk phones. We've written up how to forward calls to an AI receptionist and keep your number, with the dial codes for a cellphone and the questions to put to a VoIP provider or the IT company that runs your system.
Send the calls somewhere that answers
That's harder than it sounds. Forwarding to a colleague's cellphone just moves the problem: in a wide outage, they may be in the dark too. Voicemail stops the call ringing out, but a caller with a burst pipe may not leave a message, and may ring someone else instead.
What holds up is a person or service somewhere with power, or an AI receptionist. Both take the call. The difference is what happens next.
Our AI receptionist answers on its own telephone number, carried by a telephony provider rather than by anything in your office. Your line, or the network behind it, forwards calls there. When a call comes in, the assistant does what it does on any other day.
Routine questions get answered from the knowledge base built from your own material, such as your services, areas and trading hours. Appointments get booked, moved or cancelled in your connected calendar, so someone who rings during the outage ends the call with a time instead of a promise. Where somebody's available, it transfers the call live. Where nobody is, it books a callback, and in an outage that callback list is what your team works through when the power comes back. It can also send the caller the details on WhatsApp, so they've got something in writing.
We should be honest about the limits, too. The assistant runs on its own providers, and they can have bad days as well. That's why "If the platform goes down, where do your calls go?" is on our list of questions to ask any AI voice agent provider. Put it to us too.
When the power comes back
Work the list. Whatever answered during the outage, whether that was an AI receptionist, an answering service or voicemail, will have left callers waiting for a call back. Decide in advance who rings them, in what order, and where that list lives, so it doesn't fall to whoever happens to be first through the door.
That routine matters more than any tool. We'll say it again: no system rescues a callback nobody makes.
Test it before you need it
Pick a quiet time, warn the team, and walk through it:
- Switch off the router and the phone system at the wall, then ring your business number from a cellphone on another network. Note exactly what a caller hears.
- Switch off the cellphone that carries your published or backup number, and ring it. If the forward is set up properly, the call goes to its destination instead of ringing out or reaching voicemail.
- Listen to what greets the caller. It should be your own greeting, not a network announcement.
- Make a test booking through the assistant and check that it lands in the calendar.
- Write down how to switch everything back, including the codes or portal steps to cancel each forward. Keep that note where the whole team can find it.
Do it again whenever you change phone provider, move offices or change who carries the backup phone.
How we set it up
When we build an AI receptionist, telephony gives it a number to answer, new or forwarded from your existing line, and we agree with you which calls it should take and when. A knowledge base built from your own material stops it guessing. Calendar access lets it book. An escalation rule decides when it hands over to a person, and whose phone a transfer rings.
The voice minutes and telephony behind all that are billed by whichever provider carries the calls, separately from our fee. They're estimated in your quote rather than discovered later.
Not sure what your phones do when the power goes? Run the test above first. It'll tell you which fix you need before you spend anything.