VoIP • Business continuity

How to keep your VoIP phones online through any outage

National load shedding is suspended, but power and internet still drop locally. Here is the practical, three-layer plan that keeps a South African business reachable when they do.

Last verified 12 June 2026
By the WhichVoIP editorial team
7 min read

SuspendedNational load shedding, per Eskom (2026)

Power + lineVoIP needs both to stay up

3 layersPower, internet, device failover

~100 kbpsBandwidth per call (ITU-T G.711)

The short answer

What happens to my VoIP phones when the power or internet goes down?

VoIP depends on both electricity and an internet connection, so if either drops without a backup, your phones drop too. The fix is a three-layer plan: a small UPS to keep your router and handsets powered, a second internet path such as an LTE or fixed-wireless failover, and a mobile-app or cloud auto-attendant so calls still reach someone. Together they keep you reachable through a local outage.

Days South Africa ran without load shedding by March 2026

Resilience layers: power, internet, device

Bandwidth per concurrent call (ITU-T G.711)

Things every plan needs: backup power and a second path

A Small South African Office Staying Connected During A Power Outage With A Ups And Router Lit Up — A modest UPS and a backup connection are all it takes to keep the phones answering when the grid or the fibre blinks.

Why VoIP needs a continuity plan

An old analogue line drew power from the exchange. VoIP does not, so the resilience has to live in your office instead.

A VoIP call turns your voice into data packets and sends them over the internet. That call depends on a working router, powered handsets or computers, and a live connection. Break any link in that chain and the call fails. The upside is that each link has a cheap, well-understood backup.

The VoIP dependency chain, and where backups go

The honest 2026 picture

The threat has changed since the worst years, and a continuity plan should reflect that rather than fight the last war.

Eskom declared an end to national load shedding in early 2026, and the country passed 300 consecutive load-shedding-free days by March. So the daily, scheduled blackout that once justified an inverter in every office is no longer the norm.

What has not gone away is local interruption. Parts of Gauteng still see scheduled load reduction in peak windows where infrastructure is under strain, cable and equipment theft takes connections down without warning, and ordinary faults still happen. For a business, a missed call costs the same whatever caused the outage. The goal is simply to stay reachable.

✓

Bottom line: plan for outages, not specifically for load shedding. A setup that survives a two-hour power cut or a fibre fault will survive load reduction too, and it is cheaper than the heavy inverter rigs of a few years ago.

Three layers of resilience

Match the layer to your size. A two-person office needs the basics; a busy team needs redundancy at every stage.

Start here

Power

UPS

Keeps liveRouter + handsets
RuntimeHours, not minutes
CostLow

Internet

Failover

Backup pathLTE / fixed wireless
SwitchoverAutomatic
CostMedium

Device

Mobile

WhereSoftphone app
RoutingCloud auto-attendant
CostUsually included

Layer 1: keep the power on

Most of your phone system draws very little power. A modest uninterruptible power supply (UPS) sized for your router and a couple of handsets will run them for hours, long past a typical local outage. Put the router and your core devices on it and you have solved the most common failure point first.

Layer 2: give the internet a second path

If your fibre drops, a backup connection keeps calls flowing. An LTE or fixed-wireless failover on a dual-WAN router switches over automatically, so staff barely notice. This is the layer larger teams should not skip.

Layer 3: let calls follow your people

Because hosted VoIP lives in the cloud, your provider can reroute calls even when your office is dark. A softphone app on a mobile keeps staff reachable on cellular data, and a cloud auto-attendant answers professionally and routes callers to whoever is available. This layer usually comes with the service, so it is the cheapest insurance you own.

The right question is not “what happens during load shedding”. It is “can a customer still reach us during any outage”, and that you can answer for a few hundred rand.

WhichVoIP editorial view

Build your continuity plan

Step 1

Put your router and core handsets on a UPS sized for a few hours of runtime.

Step 2

Add an LTE or fixed-wireless failover on a dual-WAN router for automatic switchover.

Step 3

Install the provider’s softphone app on staff mobiles so calls reach them on cellular data.

Step 4

Set a cloud auto-attendant and failover rule so callers are answered and routed if the office is offline.

Step 5

Test it. Pull the power for ten minutes and confirm a call still gets through.

A Desk Setup With A Router, A Ups Battery Backup And An Lte Failover Modem Connected Together — Router and core devices on a UPS, an LTE failover beside it: the whole resilience stack fits on a shelf.

Our verdict

VoIP is not fragile, it is just honest about its dependencies. With load shedding suspended nationally, the case for an expensive inverter rig has weakened, but the case for basic continuity has not. A UPS on the router, an automatic internet failover and a mobile-app fallback will keep a South African business answering through almost any local outage, for a fraction of what those backups cost a few years ago.

Our recommendation: start with Layer 1 today (a UPS on your router), then add internet failover if you take a lot of calls. Ask any provider you shortlist how their cloud failover and mobile app behave when your office goes dark.

Find a VoIP provider with proper failover

We will match you with South African providers and you can ask each one exactly how their service stays up during an outage.

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Frequently asked questions

Does VoIP work during a power cut?

Only if the equipment has backup power. VoIP draws power locally, so a router and handsets on a UPS will keep working through an outage. Without backup power, the phones go down with the grid.

Is load shedding still a problem for business phones in 2026?

National load shedding is suspended, and South Africa passed 300 load-shedding-free days by March 2026. Localised load reduction, cable theft and ordinary faults still cause outages, so a basic continuity plan is still worth having.

What size UPS do I need for a VoIP phone system?

Enough to run your router and the handsets you need, for a few hours. The core networking gear draws little power, so a modest UPS usually covers a small office. Size it to your actual devices and the runtime you want.

How does VoIP fail over to mobile during an outage?

Hosted VoIP lives in the cloud, so your provider can reroute calls to a softphone app on a staff mobile over cellular data, or to a cloud auto-attendant. Set the failover rule with your provider so it happens automatically.

Do I need a second internet connection for VoIP?

It is the strongest upgrade for a call-heavy business. An LTE or fixed-wireless failover on a dual-WAN router switches over automatically if your main line drops, so calls keep flowing without anyone noticing.

Keep reading

Troubleshooting choppy VoIP calls
The VoIP migration checklist
What is a VoIP phone system?
Business wireless internet options

Sources: Eskom power-system statements on the suspension of national load shedding (2026); Eskom load-reduction notices (Gauteng peak windows); ITU-T G.711 (voice bandwidth per call). Verified 12 June 2026.

Keep VoIP Phones Online During Outages (2026 Guide)