L'équipe Texto SMS Gratuit
5 October 2026 · 11 min read
Introduction: one bar of signal in the kitchen, none in the bedroom
The scenario is so commonplace that we've stopped seeing it as abnormal. You live in a reasonably well-covered town, your carrier advertises "99% population coverage" on its maps, and yet, at home, you have to press yourself against the living room window to finish a conversation. In the bedroom, the call drops after forty seconds. In the bathroom, the phone displays "Emergency calls only".
The cause is almost never the carrier. It's in the walls: reinforced concrete, external wall insulation, double glazing with a metallic coating, basements, a central stairwell. The materials that produce good energy ratings also produce bad reception — a 700 MHz or 2100 MHz wave loses most of its energy passing through a recently insulated façade.
The good news is that for several years now there has been a free answer, built into your plan, requiring no antenna, no building work and no call to customer service: Wi-Fi calling, or VoWiFi (Voice over Wi-Fi). Your phone stops using the cell tower and routes your voice through your home internet connection, exactly as it would route a video.
This guide explains what VoWiFi actually does, what it doesn't do, how to turn it on for each operating system, and above all the four situations where it will let you down — including one involving emergency calls that's worth knowing about before you need it.
What Wi-Fi calling really is
First, let's clear up a common confusion. Wi-Fi calling is not WhatsApp, Messenger or FaceTime. Those apps also travel over the internet, but they build their own parallel network: the person you're calling needs the same app, and your phone number is nothing more than an identifier.
VoWiFi, by contrast, is a carrier feature. Your phone registers on the core network of Free, Orange, SFR or Bouygues via your internet connection rather than over the air. The practical consequences:
- You dial numbers normally, from the Phone app.
- The person you're calling sees your usual number appear.
- They can call you on your number without installing anything.
- Minutes are deducted from your plan like a standard call — so unlimited in most cases.
- Texts go through too (SMS over IMS follows the same route).
In other words: nothing changes for you or for the people calling you, except that your voice travels down the fibre cable instead of through the neighbourhood tower. It's free and it's included: no French carrier charges extra for VoWiFi.
VoWiFi, VoLTE, 5G: who does what
| Technology | Voice carrier | Main benefit |
|---|---|---|
| 2G/3G (GSM) | Legacy mobile network | Being switched off in France |
| VoLTE | 4G network | HD quality, faster call setup |
| VoWiFi | Your router / any Wi-Fi | Indoor coverage, travel abroad |
| Vo5G | 5G network | Marginal for voice so far |
Carriers moved voice onto VoLTE (voice over 4G) several years ago, and Arcep is overseeing the gradual shutdown of the 2G and 3G networks — Orange and SFR have announced staggered switch-off timetables across the second half of the decade. That shift has a direct side effect: older phones that support neither VoLTE nor VoWiFi are gradually losing the ability to make calls at all, even when they show full signal bars. If a relative has been complaining for a few months that calls are impossible on an eight-year-old handset, that's almost certainly why.
Turning on Wi-Fi calling: how to do it
The option is switched off by default on a fair number of devices, and that's precisely why millions of people keep chasing signal up and down their hallway.
On iPhone
- Open Settings → Apps → Phone (on iOS 18 and earlier: Settings → Phone).
- Tap Wi-Fi Calling.
- Turn on Wi-Fi Calling on This iPhone.
- A screen asks you to confirm your emergency address. Enter it accurately (see below — it matters).
If you have a cellular Apple Watch or an iPad linked to the same account, a second toggle, "Add Wi-Fi Calling For Other Devices", will appear.
On Android
The path varies by manufacturer, but always revolves around the same words:
- Samsung: Settings → Connections → Wi-Fi Calling.
- Google Pixel: Settings → Network & internet → SIMs → Wi-Fi calling.
- Xiaomi / Redmi: Settings → SIM cards & mobile networks → select the SIM → Wi-Fi calling.
On dual-SIM phones, the option is set line by line. Plenty of users enable it on the first SIM and then wonder why the second stays silent.
Checking that it works
The most reliable sign is in the status bar: a Wi-Fi icon next to your carrier name, or the words "Wi-Fi Calling" / "VoWiFi" / "WiFi Calling" in place of the signal bars. To test it unambiguously, turn off mobile data, switch on airplane mode, then re-enable Wi-Fi only: if your phone still shows Wi-Fi calling mode and you can place a call, you're up and running.
The four blind spots of VoWiFi
This is the part carriers' help pages skim over. Wi-Fi calling works very well, right up until the day it doesn't — and it's better to know why in advance.
1. Emergency calls and your address
When you call 112, 15 or 18 over the mobile network, your position is passed automatically to the emergency services via the cell tower and the phone's GPS. On VoWiFi, that location data doesn't exist: the network has no idea where your router is.
That's the reason for the emergency address you're asked for during setup. It is forwarded to the emergency call centre if you dial an emergency number over Wi-Fi. Two practical consequences:
If you move house, go back and update the emergency address in your settings. And if you call the emergency services from somewhere else while connected to an unfamiliar Wi-Fi network, state your actual location immediately: the address showing on the operator's screen may well be your own living room, 300 km away.
In practice, most phones will try to fall back to the mobile network for an emergency call if any signal at all, however weak, is available. But that's not guaranteed in a deep basement.
2. Handover from Wi-Fi to mobile mid-call
You start a conversation at home over Wi-Fi, then head out. The moment you leave the router's range, the phone has to transfer the call to 4G. This switch — the handover — works well where the carrier has implemented it properly, and drops the call where it hasn't, particularly if you're walking out into an area that already has poor coverage.
The reverse (mobile → Wi-Fi as you arrive home) fails even more often. If your long conversations matter to you, get into the habit of starting the call wherever you intend to stay.
3. The quality of your home network
A voice call uses very little bandwidth: around 25 to 100 kbit/s in each direction. Throughput is never the problem. What is, is stability: latency, jitter, packet loss. A Wi-Fi network saturated at 9 p.m. by three video streams, a router shut inside a hallway cupboard, or an old, badly configured range extender will give you choppy audio even though the speed test reads 300 Mbit/s.
The fixes that help, in order of effectiveness:
- Move the router to a central point in the home, up high, and out of any closed cabinet.
- Force the phone onto the 5 GHz band when you're in the same room as the router, and stay on 2.4 GHz when you're far away (better at passing through walls).
- Replace a cheap extender with a proper whole-home mesh Wi-Fi system, which keeps a single network name and handles the move from one node to the next cleanly.
- Enable voice prioritisation (QoS / WMM) in the router's admin interface where available.
4. Public Wi-Fi and corporate networks
VoWiFi relies on specific protocols (IPsec over UDP ports 500/4500). Plenty of hotel, hospital, corporate and public-venue networks block them. The phone shows the Wi-Fi icon… but the call fails. It's neither your fault nor the carrier's: it's the venue's firewall.
Abroad: the most underrated use case
Here's the point that saves the most money, and that almost nobody mentions. When you're connected via VoWiFi outside France, your French carrier handles the call as though it were placed from within France.
In concrete terms, from a hotel Wi-Fi network in Montreal, Bangkok or Marrakech:
- Calling a French number is deducted from your domestic plan, so generally unlimited.
- Receiving a call from someone back in France costs you nothing.
- Texts work the same way.
That's the difference between a three-figure roaming bill and zero. One caveat, though: terms vary from one carrier to another, some restrict VoWiFi outside the European Union, and calls to a local foreign number are still billed at international rates. Check your plan's pricing sheet before you leave, not while you're away.
One logistical detail that matters: to take advantage of VoWiFi abroad, the phone has to last the day. Between constant Wi-Fi, GPS and photos, battery life melts away. A 20,000 mAh power bank in your backpack settles that for the day, and a universal travel plug adapter stops you arriving in your room with an incompatible plug.
When VoWiFi isn't enough: the other options
The femtocell (or "coverage box")
Some carriers offer a small box that plugs into your router and creates a mini 4G cell inside your home. It's technically superior to VoWiFi — handover with the outdoor network is handled properly, and every device benefits, including those that don't support Wi-Fi calling. These units are generally reserved for customers identified as poorly covered, sometimes with a security deposit. You have to ask customer service explicitly, backing up your case with measurements.
Signal boosters sold online
Let's be clear: in France, installing a mobile repeater as a private individual is illegal without authorisation. Arcep regularly points out that these boxes, widely sold online, disrupt the network for the entire neighbourhood and expose their user to penalties. Only carriers may deploy them. Steer clear, however miraculous the listing sounds.
Good old-fashioned landline handsets
If your router provides a phone line (which is the case with virtually every fibre plan), a cordless DECT landline phone plugged into it remains the most reliable option for long conversations at home, with battery life and audio comfort no smartphone can match. For older people in particular, it's often a better fit than hunting for the right room in the house.
Headsets: the quiet winner
Many problems blamed on the network actually come from the phone's microphone, degraded by an ill-fitting case or a clogged grille. A Bluetooth earpiece with noise reduction often improves the clarity of a VoWiFi call more than switching carriers would.
Measure before you conclude
Before declaring that "there's no signal", get some hard numbers. On Android, network diagnostic screens show received signal strength in dBm (Settings → About phone → Status). On iPhone, access is more locked down, but network measurement apps do the job.
Useful benchmarks:
| Measured level | Interpretation |
|---|---|
| −50 to −80 dBm | Excellent, no issues expected |
| −80 to −95 dBm | Fine, calls are stable |
| −95 to −105 dBm | Weak: drops likely indoors |
| Below −110 dBm | Unusable, turn on VoWiFi |
Take a reading in every room, at two different times of day. If the figures are good outside and dire inside, the problem is architectural, and VoWiFi is the answer. If they're bad everywhere, including out on the street, it's a coverage issue: the coverage maps published by Arcep (monreseaumobile.arcep.fr) let you compare all four carriers at your exact address, and switching carriers can then change everything.
The recap
- Wi-Fi calling is free, included and active in two minutes on every French carrier.
- It solves nearly all reception problems inside a home.
- Enter an accurate emergency address and update it if you move.
- Abroad, it turns a roaming bill into zero euros on calls back to France.
- The real limitations are mid-call handover, filtered public Wi-Fi, and the stability of your own home network.
- Never buy a mobile signal booster: it's illegal for private individuals.
In the vast majority of cases, poor reception at home isn't a problem with your plan. Switching carriers for that reason alone often means paying to fix something a single toggle in your settings would have sorted out for free.
