What is Wi-Fi Calling and How Does it Work? | AT&T

What is Wi-Fi calling and how does it work?

Learn what Wi-Fi Calling is, how to make calls using Wi-Fi Calling, and how to activate it on iPhones and Android devices.

Info at a glance

What is Wi-Fi Calling?
Advantages of built-in Wi-Fi calling
Disadvantages of built-in Wi-Fi calling
Advantages and disadvantages of Wi-Fi calling apps
Is Wi-Fi calling safe?
How do I turn Wi-Fi calling on and off?
Is Wi-Fi calling free for international calls?
Does Wi-Fi calling use cellular data? Can I force my device to use Wi-Fi calling only?
Wi-Fi calling benefits for business
How do I know if Wi-Fi calling is working?

What is Wi-Fi Calling?

Wi-Fi calling—also known as Voice over Wi-Fi® (VoWiFi)—lets your phone make calls and texts using a Wi-Fi network, instead of your provider’s cellular network. When enabled, Wi-Fi calling will automatically activate when your cellular signal is weak or unavailable.

You can turn this feature on in your phone’s Settings app. Another kind of Wi-Fi calling is specific to third-party apps (as opposed to your device’s native calling app). Examples include WhatsApp, Skype, Zoom, Google Meet, and Viber. These allow anyone using the app to call and text other app users.

These apps can be used with Wi-Fi devices like tablets that aren’t on an active cell phone plan or aren’t SIM-enabled.

Want to learn more about the types of Wi-Fi calling? Read on.

Advantages of built-in Wi-Fi calling

Wi-Fi calling is a great plan B for when your cell signal is weak or there’s a network outage.

Better coverage: Calls over Wi-Fi come in handy in areas with a weak cell signal but a good Wi-Fi connection.

Flexibility and mobility: If your cell phone supports Wi-Fi calling, you can make and get calls from just about anywhere.

Easy access to contacts and no third-party apps needed: Wi-Fi calling service is a feature integrated into your mobile device. This means it can access your phone book, and the person on the receiving side doesn’t need to manually download an extra app.

No impact on your mobile plan’s data or minutes: If you don’t have a plan with unlimited data, Wi-Fi calling lets you call and text without using your plan’s allotted data or minutes.

Are there any drawbacks to built-in Wi-Fi calling?

If you sometimes experience a weak cellular signal or want to avoid paying hefty phone bills while traveling abroad, Wi-Fi Calling would be a great option for you. However, you may want to consider some of the downsides, too.

Reliance on Wi-Fi + internet

Unstable or weak Wi-Fi or the internet that supports it can cause poor-quality calls, speech lag, and dropped calls. Call quality also reduces as more devices share a Wi-Fi network, consuming bandwidth.

Also, if your home internet plan has a data cap, using Wi-Fi may use up the internet data faster.

Drained battery

Your device keeps switching between Wi-Fi calling and cellular networks? Then it’s likely your battery will run down faster than if you stay connected to just one network.

Dropped calls when both networks are good

With Wi-Fi calling turned on, your device keeps searching for and connects to the best voice service available, even during an active call. This switching can cause calls to drop if both cellular and Wi-Fi networks are available and stable.

Less accurate location during emergencies

When you make a call over Wi-Fi, your location isn't as accurate as when using the cell network. This could make it hard to pinpoint your location if you’re making an emergency call.

Advantages and disadvantages of Wi-Fi calling apps

Wi-Fi calling apps (like WhatsApp, Skype, Zoom, Google Meet, and Viber) have benefits and drawbacks.

Advantages of Wi-Fi calling apps

Web interface: Some apps also have a web interface, so you can use the app on other Wi-Fi–connected devices.

Extremely secure: Apps like WhatsApp and Viber use end-to-end encryption, ensuring your data is safe and private.

Free calls, no cellular plan needed: All VoIP apps offer free domestic and international calls over Wi-Fi.

Additional features: Most VoIP apps have additional features, giving you an enhanced call experience. These added-value features include video calling, screen sharing, group calls, and text messaging. Some apps let you change your video call background, record your calls, and even have your calls transcribed.

Disadvantages of Wi-Fi calling apps

Not 100% tied to Wi-Fi: While these apps can and do use Wi-Fi to make calls when connected to Wi-Fi, they can use cellular data for calls and texts if Wi-Fi is weak (and your device has an active cellular plan). You can change this by going to your app’s setting and making sure that Cellular data or Use cellular data is toggled off.

Use is tied to the app itself: Most of these apps only allow calls and texts between users who have downloaded the app.

Is Wi-Fi calling safe?

All calls made from your smartphone, including Wi-Fi calls, should be encrypted by your provider.

If you’re using a public Wi-Fi network—like in a café or airport—there’s a chance someone could intercept your Wi-Fi calls. To keep your calls and data safe, use Wi-Fi calling only on secure, password-protected Wi-Fi networks.

If you’re using a home Wi-Fi network, here’s how to secure your home network data:

Using a VPN on your home network

Maintaining your router’s security patches

Regularly updating your Wi-Fi calling apps

Using smartphone security apps like AT&T ActiveArmor can help provide an additional level of security when connected to public Wi-Fi networks.

Are Wi-Fi calls private?

Keep in mind that, while it takes a sophisticated hacker to intercept your Wi-Fi calls, that doesn’t mean that the content of your Wi-Fi calls are 100% private. Both cell phone providers and third-party app developers must adhere to government demands for customer communications. So, while it’s unlikely, it’s still possible that your conversations can be viewed by third parties, including government agencies.

How do I turn Wi-Fi calling on or off?

Most devices don’t have Wi-Fi calling turned on by default. It’s important to check if your provider supports Wi-Fi calling in the first place—not all providers do.

The exact steps to turn on Wi-Fi calling may differ depending on your phone model and OS, but here are the general steps:

Enable or disable Wi-Fi calling on Apple iPhone

Go to the Settings app.
Tap on Cellular (you can also select Apps, then Phone).
Tap on Wi-Fi Calling.
Toggle Wi-Fi calling to On (it should turn green).
A screen may pop up asking for your emergency address. This is used for 911 calls. Fill in the information as needed and hit Done.

Enable or disable Wi-Fi calling on Android

Open your Phone app.
Tap on the three-dot menu icon at the top right corner of the screen.
Select Settings.
Look for Wi-Fi Calling and toggle the switch to On.
A screen may pop up asking for your emergency address. This is used for 911 calls. Fill in the information as needed and hit Done.

Is Wi-Fi calling free for international calls?

All Wi-Fi calls to U.S. numbers are free of charge. This is true for both your built-in device Wi-Fi calling and app-based Wi-Fi calling.

When traveling abroad, you can use apps like WhatsApp, Google Meet, Zoom, etc. for calls and texts as long as you are connected to Wi-Fi. However, some apps may be blocked in certain countries.

If you’re traveling abroad and want to make phone calls and send texts, check out travel packages from your provider.

For international Wi-Fi calling with AT&T, charges depend on where the call originates and where it’s received.

Learn more about how to use your cell phone internationally.

Does Wi-Fi calling use cellular data? Can I force my device to use Wi-Fi calling only?

Even with built-in Wi-Fi calling or app-based Wi-Fi calling, your device can still end up using your cellular data.

Built-in Wi-Fi calling is a feature that will chose whichever network is the most strong and stable—whether that’s cellular or Wi-Fi. It may switch continually between the two if the network’s strength changes.

You can force your built-in Wi-Fi calling to use Wi-Fi only. Simply enable Wi-Fi calling in your device’s Settings app, and then put your device into airplane mode. This will keep your device from connecting to a cellular network.

App-based Wi-Fi calling is capable of using cellular data if you allow the app to access it. To force an app to only use Wi-Fi data, go to your device Settings, and select the app. Then toggle off the Cellular data option.

Wi-Fi calling benefits for business

The benefits of Wi-Fi calling, both built-in and app-based, are similar for consumers and businesses. For instance, both options can offer savings on international calling (although savings depend on your regular phone plan’s international calling options).

Built-in Wi-Fi calling

Employees are not limited to a specific workstation and can work wherever there’s good Wi-Fi
Great for facilities with strong Wi-Fi and internet, but weak or inconsistent cell phone signals

App based Wi-Fi calling

Can offer significant cost savings for international calling
Can help businesses avoid roaming charges when employees travel

However, because the system is app‑dependent, there may be limits to which apps are available in your clients’ or partners’ countries.

How do I know if Wi-Fi calling is working?

Wondering how to make sure Wi-Fi calling is active on your device? Follow these tips:

Check your provider's requirements: Some providers require enabling certain settings, owning a particular type of phone, or having a specific plan for the Wi-Fi calling to work.
Check your cell phone's settings: Double-check the Settings app on your cell phone to see if Wi-Fi calling is turned on.
Check your status bar: An icon or text usually will appear in your phone's status bar at the top of the screen once the Wi-Fi calling is in use.
Test your service: The ultimate way to verify Wi-Fi calling is working is to put it to the test. Set your cell phone to airplane mode, turn on Wi-Fi calling, and try calling or texting. If it goes through, you’ll know Wi-Fi calling is working.

Remember, calls and texts over Wi-Fi rely on a strong and stable internet connection. If your Wi-Fi signal is weak or the internet network is slow or congested, your calls and texts may not go through.