Wi-Fi calling is a feature of your phone and your mobile carrier that lets you make and receive ordinary calls and texts over a Wi-Fi connection instead of a cell tower. You keep your normal number and the normal Phone app, and your plan bills the call like any other. Carriers offer it mainly for places with weak or no mobile signal. Whether it saves money abroad depends on your carrier: some US carriers make Wi-Fi calls home free, while O2 in the UK says the feature does not work outside the UK at all.
How carrier Wi-Fi calling works
With Wi-Fi calling on, your phone reaches your carrier over the internet instead of over the air, and the carrier still connects the call. EE's help page puts it plainly: "Although WiFi and the internet are used to connect your mobile phone to the EE network, EE still makes it work by connecting the call or delivering the text for you." Verizon describes the same design, with the Wi-Fi connection used "to route calls and messages to the Verizon network".
That design explains how the feature behaves:
- It is billed as a normal call. EE says your call and text charges "are the same when you use WiFi Calling". Wi-Fi calling changes the route, not the price.
- It does not use your mobile data. Verizon and EE both say Wi-Fi calls don't count against your plan's data allowance. EE estimates that a 30-minute call uses around 10MB of Wi-Fi data. The owner of the Wi-Fi network may still charge you to connect, as some hotels and trains do.
- Your phone picks the route. Apple presents Wi-Fi Calling as the way to call in areas with little or no cellular coverage. O2 says a phone with a strong mobile signal may prefer 4G or 5G calling instead.
- Calls can hand over. On EE, if you walk out of Wi-Fi range during a call, the phone moves the call to 4G. With no 4G signal, the call drops.
Because the carrier handles the call, Wi-Fi calling only works if your carrier supports it on your phone. Apple keeps a list of carriers and the iPhone features each supports, including Wi-Fi Calling.
How to turn on Wi-Fi calling
iPhone
From Apple's guide:
- Open Settings and tap Cellular.
- If your iPhone has more than one SIM, choose the line you want.
- Tap Wi-Fi Calling and turn on Wi-Fi Calling on This Phone.
- Tap Enable, and enter or confirm your address for emergency services if asked.
When the feature is active, "Wi-Fi" appears in the status bar while you view Control Center. Turn it on before you travel. Verizon, for one, says an iPhone must be connected to its network in the US to switch Wi-Fi Calling on, and that it "can't be activated after you leave the country".
Android
Menus differ between manufacturers. Google's instructions are Settings > Network & internet > SIMs > your carrier's SIM > Wi-Fi calling. If that option is missing, Google says your carrier doesn't support the feature. On Samsung Galaxy phones, Samsung's guide is Settings > Connections > Wi-Fi Calling. That screen also has a calling preference and, on some carriers, a "When roaming" or "Roaming network preference" setting that decides whether the phone prefers Wi-Fi or the cellular network abroad.
Emergency calls
Fill in the emergency address when your phone asks for it. Apple says an iPhone uses the cellular network for emergency calls whenever it is available and only falls back to Wi-Fi Calling when there is no cellular service. Over Wi-Fi, your location is less reliable. Verizon warns that a 911 call may not reach the nearest emergency service if you are not at your registered address, and O2 says a 999 operator may need to ask where you are calling from because Wi-Fi calls don't show location information.
How carriers bill Wi-Fi calls to and from abroad
Carriers set very different rules for Wi-Fi calls made outside the home country. Three examples, checked 3 October 2026:
| Carrier | Works abroad? | Wi-Fi call home | Wi-Fi call to any other country |
|---|---|---|---|
| Verizon (US) | Yes | Free to US numbers | Charged at your international long distance plan, or pay-as-you-go international rates without one |
| AT&T (US) | Yes | Free to US numbers | Included in the International Day Pass daily fee; billed per minute on Passport or without a roaming add-on |
| O2 (UK) | No: "WiFi Calling isn't currently supported outside of the UK" | Not available | Not available |
Sources: Verizon's Wi-Fi Calling FAQs, AT&T's page on international Wi-Fi calls and O2's Wi-Fi Calling help.
Verizon plays a voice prompt before an international Wi-Fi call to warn that charges may apply, so you can hang up before it connects. AT&T says calls to US toll-free numbers often won't complete from abroad, and if they do, they are billed as international calls. AT&T's pay-per-use rate for Wi-Fi calls to international numbers depends on the country you are calling from.
In the UK, EE's help page describes WiFi Calling as needing "a WiFi connection in the UK" and does not cover use abroad. If you are on a UK network, don't count on Wi-Fi calling to avoid roaming charges unless your provider's own help pages say it works where you are going.
Wi-Fi calling from home doesn't make international calls cheaper either. Verizon bills a Wi-Fi call from the US to another country at your international long distance rate, the same as a call over its cell network. For carrier-specific rates, see our guides to Verizon international calling rates and the AT&T international plan.
Wi-Fi calling vs calling apps such as WhatsApp and CallSky
Calling apps also run over Wi-Fi, but they work independently of your carrier. The app company connects the call and bills you, if it charges at all. CallSky is our product, so weigh our view with that in mind.
| Carrier Wi-Fi calling | CallSky (our product) | ||
|---|---|---|---|
| Who you can call | Any phone number | Other WhatsApp users | Landlines and mobiles in 180+ countries |
| Cost | Your carrier's normal rate for that call | Free, though WhatsApp notes that data charges may apply | Per minute from prepaid credit, such as $0.03/min to US numbers |
| Setup | A switch in your phone's settings, if your carrier supports it | Both people need the WhatsApp app | The iPhone or Android app or a web browser, plus credit from $5 |
| Abroad | Depends on your carrier (see above) | Works over Wi-Fi or mobile data | Works over Wi-Fi or mobile data |
CallSky rate as of . WhatsApp's pricing note is from its calling page.
In practice, carrier Wi-Fi calling suits home or the office when the signal is poor, because there is nothing to install and people see your normal number. WhatsApp is the obvious choice when the person you are calling already uses it. For a landline, a relative who isn't on WhatsApp, or a call from a hotel where your carrier's Wi-Fi calling is blocked or billed at international rates, an app that dials ordinary numbers, such as CallSky, charges per minute from credit instead.
For more on free app calls, see whether WhatsApp calls are free. Apps that place calls over Wi-Fi are compared in our guide to the best Wi-Fi calling apps, and if the built-in feature is misbehaving, see what to do when Wi-Fi calling is not working.