WiFi calling lets your smartphone make and receive calls and texts using a WiFi network instead of a traditional cell signal. When your cellular connection is weak, your phone automatically switches to a trusted WiFi network to keep you connected, using your regular phone number.

How Does WiFi Calling Work?

At its core, WiFi calling uses Voice over Internet Protocol (VoIP) technology to route your calls over the internet instead of cell towers. When your phone detects a poor cellular signal but a strong WiFi connection, a system called the IP Multimedia Subsystem (IMS) intelligently reroutes your call's voice data through the WiFi network.

This process breaks your voice into tiny digital packets, sends them over the internet, and reassembles them on the other end—all in the blink of an eye. This seamless handoff is what prevents your call from dropping when you're in a cellular dead zone.

A flowchart demonstrates the WiFi calling process, moving from a weak signal to an automatic switch to a WiFi call.

Benefits of WiFi Calling

This feature isn't just a technical trick; it solves common and frustrating mobile phone problems. The global VoWiFi market was valued at USD 7.03 billion and is expected to explode to USD 50.52 billion by 2033, driven by our need for constant connectivity. You can explore the data in this report from Market Data Forecast.

  • No Cell Signal? No Problem: Its biggest advantage is providing clear calls in areas with poor cellular reception, like basements, high-rise buildings, or rural locations.
  • Save on International Roaming: By connecting to WiFi abroad, you can often call numbers in your home country without incurring expensive international roaming fees.
  • Better Indoor Coverage: Thick walls and building materials can block cell signals. WiFi calling bypasses this, offering a strong, reliable connection indoors.

Three hand-drawn icons illustrating benefits of a service: clear calls at home, lower international roaming, and battery saving on a smartphone.

Limitations of WiFi Calling

While incredibly useful, WiFi calling isn't a perfect solution and comes with a few important trade-offs.

  • Depends on Internet Quality: Your call quality is only as good as your WiFi connection. A slow, congested, or unstable network can lead to choppy audio or dropped calls. If you're having issues, our guide on what to do when WiFi calling is not working has practical fixes.
  • 911 Location Issues: This is a critical safety concern. Emergency services may have difficulty pinpointing your location, as the call originates from an IP address, not a cell tower. Always be prepared to state your exact location.
  • Carrier Restrictions: Not all mobile carriers or phone models support WiFi calling. While most major providers offer it, some smaller or international carriers may not.

How to Enable WiFi Calling

Getting this feature turned on is usually a piece of cake. It's built right into your smartphone's operating system, so there's no need to download an app.

Smartphone screen illustrating the Wi-Fi Calling option enabled within the device's settings menu.

Enabling on iPhone

For iPhone users, enabling WiFi calling takes just a few taps in your settings. For a complete visual walkthrough, check out our detailed guide on how to set up WiFi calling on your iPhone.

Enabling on Android

On Android devices, the steps are similar but may vary slightly by manufacturer (Samsung, Google, etc.). You'll typically find the toggle under Settings > Network & Internet > Calls & SMS. We are preparing a detailed guide for Android users, which will be available soon.

Carrier Coverage for WiFi Calling

Support for WiFi calling has become standard among major mobile providers.

  • US Carriers: All three major US carriers—AT&T, T-Mobile, and Verizon—fully support WiFi calling on compatible devices. This also includes most MVNOs (like Mint Mobile or Visible) that use their networks.
  • International Carriers: Support is growing globally, but it's not universal. Before traveling, it's always best to confirm with your provider to understand their specific policies and any potential costs.

WiFi Calling vs VoIP Apps

It's easy to confuse your phone's built-in WiFi calling with third-party VoIP apps like Skype, WhatsApp, or CallSky, but they serve different purposes. Native WiFi calling is an extension of your mobile service, using your existing phone number and requiring carrier support.

Dedicated VoIP apps like CallSky are more flexible alternatives that operate independently of your mobile carrier. This means they work even if your carrier doesn't support WiFi calling. CallSky offers additional advantages, such as:

  • Works on Any Device: Make calls from your phone, tablet, or laptop.
  • Better International Rates: Often provides significantly cheaper rates for calling abroad compared to mobile carriers.
  • Business Features: Includes tools like shared credits and team management that standard mobile plans lack.

CallSky is a more powerful and flexible solution for users who need more than just a backup for poor cell signal, especially for international communication or business use.

Ready to try WiFi calling? See our guide to the Best WiFi Calling Apps.