Wi-Fi calling was first introduced in iOS 8. The new feature was met with a virtual round of applause from all iPhone, iPad and iPod Touch users. Basically, Wi-Fi calling lets you place and receive phone calls and text messages if you have a Wi-Fi connection in an area with little or no cellular coverage.
By default, Wi -Fi calling is not enabled on your iPhone. That means you will have to activate it. Keep in mind that once you have enabled Wi-Fi calling, your iPhone will automatically switch to Wi-Fi, and if you move out of an area covered by Wi-Fi, your iPhone will switch between cellular and Wi-Fi networks to maintain a stable connection during a call.
1. How to enable Wi-Fi calling on your iPhone
To activate Wi-Fi calling on your phone, the following steps will help you
Step 1: Open the Setting app on your iPhone
Step 2: Scroll down and tap Phone
Step 3: Tap Wi-Fi calling under Calls section
Step 4: Enable Wi-Fi calling on this iPhone.
If you encounter a problem with Wi-Fi calling or simply you don’t want to use it, you can disable it by sliding Wi-Fi calling button to the left.
2. How to use Wi-Fi calling along with Continuity
Normally, Wi-Fi calling does not usually work with the Continuity feature. Therefore, you will not be able to place or receive calls on your iOS devices like a Mac or an iPad if you activate Wi-Fi calling.
If you own an iPhone running iOS 9 or a Mac running OS X EL Capitan, you can use the Continuity feature along with Wi-Fi calling.
To enable the Continuity feature, you can follow the steps below
Step 1: Launch the Settings app
Step 2: Select Calls on Other Devices under the Wi-Fi calling option.
Step 3: Select Add Wi-Fi Calling For Other Devices. This step allows other iOS devices signed into your iCloud account to make and receive calls even when your phone is not nearby.
With iOS 9.3 update, Wi-Fi calling is now available for all four major US carriers including T-Mobile, Sprint, AT&T, and Verizon.
If you are an AT&T subscriber, iOS 9.3 allows you to make international Wi-Fi calls, which will help you stay in touch while you are travelling abroad.