How do I make Wi-Fi calls?
Once you set up Wi-Fi Calling, you’ll make Wi-Fi calls like you’d make traditional voice calls. In order to provide you with the most reliable experience, calls will use the cellular network when available. If you’re using an Android device, then you can change the preferred network when traveling internationally. For Android devices, you’ll see a Wi-Fi Calling icon similar to this: when your call is over a Wi-Fi network. If you have iPhone, you’ll see "VZW Wi-Fi" in your status bar.