239 Section 9: Changing Your Settings
Important! If you are not using a new ISIM card, you will receive an Error: ERxx Invalid SIM
message. You must be using a new ISIM card to use this feature.

Activating Wi-Fi Calling

1. Ensure that the Wi-Fi connected icon displays on the Status Bar.
If prompted with an onscreen “Did you know your phone can make calls over
WiFi” popup, tap Learn and follow the remaining onscreen instructions. Tap
Next g Done.
2. From the Home screen, tap Apps g Settings g More
networks.
3. In a single motion touch and slide the Wi-Fi Calling slider to the right to turn it on.
4. If Missing 911 Address displays in the Status Bar, follow these steps to
provide 911 an address for emergency situations:
Log into my.t‑mobile.com.
Locate your customer information.
Enter your emergency location information and complete the online registration.
5. From the More networks screen, tap Wi-Fi Calling g Connection Preferences and
select a preference for use by the Wi‑Fi Calling feature:
Wi-Fi Preferred: WiFi network is preferred over cellular network when making
calls. Calling requires you to stay in the WiFi range.
Cellular Network Preferred: The cellular network is preferred over a WiFi network
when making calls.
Never use Cellular Network: Use only WiFi for calls.
Do not use Cellular Network, even if available.
6. From the More networks screen, tap the Wi-Fi Calling slider to toggle off the feature,
then tap it again to reactivate the feature and re‑register your device with the
network.
7. Confirm Wi-Fi Calling Ready displays in the Status Bar.