Wi-Fi Calling


What is Wi-Fi Calling?

Wi-Fi Calling is an enhanced calling feature, which allows you to make and receive HD voice calls, send/receive texts and pictures (MMS) using a Wi-Fi connection rather than a cellular connection.

Think of Wi-Fi Calling as a backup option when your cellular coverage is less than perfect. For example, inside buildings and basements that have Wi-Fi service, but cellular signal is weak or unavailable. Once you enable this feature, your phone will automatically switch to Wi-Fi Calling under these circumstances.

  • Make or receive phone calls through a Wi-Fi connection when there is little or no cellular coverage.
  • Wi-Fi Calling offers great value at no extra monthly charge. Calls, texts, and picture messages simply apply toward your monthly price plan.
  • Wi-Fi Calling can be used in the United States and from international countries* when calling U.S. phone numbers.
  • Calls to international numbers are billed in accordance with your international rate plan. (uscellular.com/plans/international/global-roaming)

Who is eligible for Wi-Fi Calling?

To be eligible for Wi-Fi calling you need to:

  • Have an iPhone 6S or later
  • Have HD Voice enabled on your iPhone
  • Have Carrier Settings updated to 40.2*
  • Have an iOS software updated to 13.3.1**
  • Have Wi-Fi Calling enabled on your iPhone

Activating Wi-Fi Calling

To turn on Wi-Fi calling:

  1. Go to: Home Screen
  2. Tap: Settings
  3. Tap: Phone
  4. Select Wi-Fi Calling
  5. Slide the button to the right: Wi-Fi Calling On This iPhone

You will be required to:

  • Review and Accept Terms and Conditions
  • Enter address for E911 services

Follow the onscreen instructions to enter or confirm your address for emergency services.*

Note: You will automatically see “Wi-Fi” after the U.S. Cellular name in the status bar if you’ve activated this feature and cellular coverage is poor or unavailable.

E911 Emergency Address

Set Emergency Address on iPhone

  1. Why do I need to set up an address to use Wi-Fi Calling?
    U.S. Cellular is required by the FCC to support 911 calls and collect a registered location to enable Wi-Fi Calling services. The address entered determines how a 911 call is routed. This information will be used if you’re unable to report your physical location or you call 911 using Wi-Fi Calling.
  2. How do I update my Emergency Address on my phone?
    Go to the Home Screen.
    1. Tap Settings.
    2. Tap Phone.
    3. Tap Wi-Fi Calling.
    4. Tap Update Emergency Address.
  3. What if I change locations while I’m using the service?
    You should update your registered address whenever you change locations within the U.S. and use Wi-Fi to place a call. In the event that you’re in an emergency situation and call 911 using Wi-Fi Calling where cellular service isn’t available, the device will use your registered address to handle the call.
  4. What if I am not in the US and try to call 911?
    If you travel outside of the U.S., Wi-Fi Calling does not support 911 service. Use your cellular service or a local phone to call the local emergency service number.
  5. What are the limitations of calling 911 over Wi-Fi?
    If a caller isn't at the registered address, the call may not be routed to the closest emergency service provider. Additionally, the internet service provider or network may experience congestion or an outage during the 911 call. This could cause the call to have poor quality or drop completely.
  6. When will 911 calls use my registered address?
    When using Wi-Fi Calling, 911 calls will always try cellular service in the local market first, even when the device is in Airplane Mode or cellular service is off. If cellular service isn't available and the user has set up Wi-Fi Calling, the 911 call will route using the registered address.

Important - Emergency 911 Call Limitations
When calling 911, always tell the operator where you are. Your 911 call will go over Wi-Fi only if the cellular network is unavailable. A 911 call made over Wi-Fi may be delayed or unsuccessful; for example, if the 911 system doesn't recognize the address, electrical power is out or your Wi-Fi connection isn't working. Emergency service will be sent to the address you provide above, so please update it as you change locations.

Firewall Configuration for Business Customers

Some business organizations may have firewall policies that restrict incoming UDP from the public Internet. These businesses will need to contact their IT department administrator in order to allow Wi-Fi Calling to work properly, and the following UDP ports will need to be allowed through the firewall. Outgoing TCP connections on the listed ports will also need to be allowed.

IP Range Port Num (TCP/UDP) Description Port: 500 / UDP IPsec - IKE : Device Authentication Port: 4500 / UDP IPsec - NAT traversal : Encrypted voice traffic Port: 5060 & 5061 / TCP/UDP SIP/TLS : Call Signaling Port: 443 / TCP TLS : Voice over WiFi Service Activation

Wi-Fi Calling FAQs