What is wifi calling?

Wifi calling, also called VoWiFi, places and receives calls on your usual number over a wifi connection instead of over a mobile network. To the person on the other end nothing is different: your number shows, it rings normally.

For travelling it is the most useful switch on the phone, and the one most people have never turned on.

Why it matters abroad

Your travel eSIM carries data. It almost certainly does not carry voice, because most travel eSIMs are data only by design. So the question "how do people call my normal number while I am away" has three possible answers, and only one of them is free.

• Roaming voice, which works but is charged by your operator and can be expensive outside the EU.
• Apps, which work over data but only reach people who use the same app.
• Wifi calling, which uses your own number, reaches anyone with a phone, and costs whatever a call at home costs, because as far as your operator is concerned you are at home.

That third one is the quiet winner. On hotel wifi, in a cafe, in an airport, your number simply works.

How to turn it on

Do it before you leave, while you are still on your home network. Some operators will not let you enable it for the first time from abroad.

• iPhone: Settings, Cellular, then the line, then Wi-Fi Calling.
• Android: Settings, Network or Connections, then Wi-Fi Calling. On a dual SIM phone, check the line you want.

The first time, the phone will ask for an address. That is not a formality.

The catch, and it is a real one

The address exists because emergency services need to know where you are, and a call over wifi carries no location from the network the way a mobile call does. If you dial an emergency number over wifi, the address you registered is what the dispatcher may be given.

So two things follow. Keep that address accurate. And do not treat wifi calling as a way to reach emergency services abroad: it may route to your home country's system, with your home address attached. For emergencies, use the local number on the local network, which works on any phone with signal, even with no plan at all.

The other limitations are smaller: some operators disable wifi calling while roaming, some charge for it, and the quality depends on the wifi rather than on the phone.

Quick answers

Does wifi calling cost anything?

Normally it is charged as if you were at home, so a call included in your plan stays included. A few operators treat it differently abroad, so check yours before relying on it.

Can I use wifi calling and a travel eSIM at the same time?

Yes, and it is the combination that works best. The eSIM carries data, your home line stays reachable for calls over wifi with its data roaming switched off.

Why can I not turn it on while abroad?

Some operators require the first activation to happen on their own network. Turn it on before you travel.

Does it work for emergency calls?

Not reliably, and not the way you would want. Location comes from the address you registered rather than from the network. For an emergency abroad, use the local emergency number on the mobile network.