Short answer: check the phone first. Make sure your carrier supports Wi-Fi calling, it’s turned on, and the phone shows it’s in use. Then try a different Wi-Fi network. Apple notes that not every Wi-Fi network works with Wi-Fi Calling. If calls work elsewhere but not at home, Google’s Fi help suggests turning off any VPN on the phone. Then try router changes such as the ones TP-Link documents for its routers: a firmware update, then disabling SIP ALG.

Make sure Wi-Fi calling is on and in use

  • iPhone: go to Settings > Cellular, choose the line you want if you have more than one, then tap Wi-Fi Calling and turn it on. You may be asked to enter or confirm an address for emergency services. When it’s working, “Wi-Fi” appears in the status bar in Control Center.
  • Android (Google’s Phone app): go to Settings > Network & internet > SIMs, pick your carrier’s SIM, and turn on Wi-Fi calling. Google says that if the option isn’t there, your carrier doesn’t support it. During a call, “Internet Call” or “Wi-Fi calling” appears on the notification screen. Google also notes the phone turns Wi-Fi calling off when it detects a problem, and that carriers may charge for these calls.

These menu paths are Apple’s and Google’s; other Android phones may name them differently.

Emergency calls on iPhone

Apple says an iPhone uses cellular service for emergency calls when it’s available. If it isn’t, emergency calls might use Wi-Fi Calling, and Apple says you may need to enter or confirm an address for emergency services when you turn the feature on. This section covers iPhone only; check your phone maker’s or carrier’s guidance for Android.

Is it your network?

Apple’s troubleshooting, once your carrier has confirmed the service, is:

  1. Connect to a different Wi-Fi network.
  2. Turn Wi-Fi Calling off and on again.
  3. Reset network settings.
  4. If it still fails, contact your carrier.

Apple says to wait two minutes between steps. Before resetting network settings, have your Wi-Fi password to hand in case you need to rejoin. Google’s help for its Fi service adds two checks: turn off any VPN on the phone to see if it’s the cause, and contact your internet provider if the problem happens on only one Wi-Fi network. It also notes that calling won’t work with Airplane mode on.

Router settings to try

If calls fail on your network but work on others, the router is worth a look. TP-Link documents these steps for Wi-Fi calling through its routers:

  1. Update the router’s firmware. Our guide to updating router firmware covers how.
  2. Disable SIP ALG. On TP-Link routers it’s under Advanced > NAT Forwarding.
  3. Reserve an IP address for the phone (DHCP reservation explains how).
  4. Forward UDP ports 500 and 4500 to that address (port forwarding). TP-Link labels them IKE2 and IPsec NAT traversal.

Calls that cut out in some rooms