eSIMratVoWiFi (Wi-Fi calling)
by RonyVoWiFi (Voice over Wi-Fi, or Wi-Fi calling) carries the calls and texts of your mobile line over a wifi connection instead of the cellular network. Your usual number is still used: the person on the other end sees no difference. The feature has to be supported by your carrier and switched on in the phone settings.
Why it matters when travelling
It is the perfect companion to a data-only eSIM: the eSIM covers data on the ground, and VoWiFi lets you make and take calls on your home number from the hotel wifi, with no roaming. Watch the billing: most carriers treat a VoWiFi call home as a domestic call, but policies vary outside the EU, so check your carrier's price list before relying on it.
Another use case: poorly covered spots (the basement of a riad, deep countryside, a boat in port with wifi). As long as there is wifi, your line lives.
The misconception
“Wi-Fi calling is just like WhatsApp.”
It is not: WhatsApp calls a WhatsApp account over the internet, while VoWiFi carries your real mobile line (your number, your texts, your calls to any number) over wifi. That is what lets you receive a bank code by text abroad without touching the mobile network.
In practice, device by device
On iPhone
- Settings, then Mobile Data, pick your main line.
- Switch on Wi-Fi Calling.
- A “Wi-Fi” indicator appears next to the carrier name when the feature is live.
On Android
- Settings, Network & internet (or Connections), your line, then Wi-Fi calling.
- Switch the feature on for that line.
- On Samsung, the shortcut also sits in the quick panel, “Wi-Fi calling” button.
What it changes when you compare
VoWiFi does not depend on the travel eSIM you choose: it depends on your home carrier. But it changes the equation: if you stay reachable over VoWiFi in the evening at your accommodation, a data-only eSIM is enough, and there is no need to pay more for an eSIM with a local number.
Compare eSIM plans by destination
The rat's tip: Switch VoWiFi on BEFORE leaving, from home: some carriers require a first activation on their own network. Discovering that from Bangkok is too late.
See also
Frequently asked questions
Are Wi-Fi calls free from abroad?
It depends on your carrier: most treat a VoWiFi call home as a national call, including from abroad, but that is not universal. Check your plan's price list before departure, it is written in black and white.
Does VoWiFi work with an eSIM?
Yes, both ways: your main line (physical or eSIM) can use VoWiFi while your travel eSIM provides data. And if your travel eSIM includes a number, VoWiFi then depends on that provider's support.
What is the difference between VoWiFi and VoLTE?
The transport network: VoLTE carries the call over 4G, VoWiFi over wifi. The phone switches automatically between them depending on connection quality, without dropping the call on recent networks.