Wi-Fi calling lets you make and receive calls over any available Wi-Fi connection – home or public – when you have no cellular coverage or simply want to save on call costs.

Wi-Fi calling is only available from select carriers and some device and iOS version restrictions also apply.

Carriers that support Wi-Fi calling on iOS (and OS X)

• S.: AT&T (iPhone 6 or later running iOS 9.0 or later), Sprint (iPhone 5c or later running iOS 8.3 or later), and T-Mobile (iPhone 5c or later running iOS 8.0 or later, iPad or iPod touch running iOS 9.0 or later, Apple Watch with watchOS 2, or Mac with OS X El Capitan)
• Canada: Bell, Rogers
• K.: EE, Vodafone
• Hong Kong: 3, SmarTone

How to enable Wi-Fi calling on iPhone

1. Open your Settings app.
2. Navigate to Settings > Phone > Wi-Fi Calling.
3. If required, enter your name and address for emergency services.
4. Toggle the “Wi-Fi Calling on this Phone” slider to the ON position.

When Wi-Fi calling is available, “Wi-Fi” will appear after your carrier name in the status bar. All calls will now use Wi-Fi calling instead of a cellular connection.

How to use Wi-Fi calling on iPad, iPod touch, Apple Watch or Mac (T-Mobile only)

T-Mobile customers in the U.S. have the exclusive ability to place Wi-Fi calls from their iPad, iPod touch (running iOS 9.0 or later), Apple Watch (running watchOS 2.0), or Mac (running OX X El Capitan). Wi-Fi calling on these devices will work whether you have your iPhone with you or not and will even work if your iPhone is switched off.

Follow these steps to place a Wi-Fi call from your iPad, iPod touch, Apple Watch, or Mac on T-Mobile:

How to place a Wi-Fi call from your iPad, iPod touch, or Mac

First, add your other device:

1. On your iPhone, go to Settings > Phone and toggle on Wi-Fi Calling and Allow Calls on Other Devices.
2. On your other device, sign in to iCloud and FaceTime with the same Apple ID and password that you use on your iPhone.
3. Turn on Wi-Fi Calling:
   • On your iPad or iPod touch: Go to Settings > FaceTime > Calls from iPhone and tap Upgrade to Wi-Fi Calling.
   • On your Mac: Open FaceTime and choose FaceTime > Preferences > Settings and select Calls From iPhone > Upgrade to Wi-Fi Calling.
4. When a six-digit code appears, enter it on your iPhone and tap Allow.

For Apple Watch, Wi-Fi calling is enabled by default.

Place a Wi-Fi call from iPad, iPod touch, or Mac

1. Open FaceTime.
2. Tap Audio.
3. Enter a contact or phone number and tap the phone icon.

You can also place a call by tapping a phone number in Contacts, Mail, Messages, Safari, and other apps.

Place a Wi-Fi call from Apple Watch

1. Open the Phone app.
2. Choose a contact.
3. Tap the red phone icon.

Troubleshooting Wi-Fi calling on iPhone

Provided your carrier supports Wi-Fi calling on your device an iOS version, you can follow these steps to troubleshoot issues: (Allow two minutes between steps to see if it solves the issue.)

• Go to Settings > Phone > Wi-Fi Calling and make sure that Wi-Fi Calling is ON.
• Restart your iPhone or other device.
• Connect to a different Wi-Fi network. Apple notes that not all Wi-Fi networks will work with Wi-Fi Calling.
• Turn Wi-Fi calling OFF and then ON
• Go to Settings > General > Reset and tap Reset Network Settings.

For carrier-specific support in the U.S., use these links:

• Sprint
• AT&T
• T-Mobile

Sources: CNet; iPhoneFAQ; Apple

Image credit: Alexas_Fotos via Pixabay