No voice calls on AT&T

[ChrisRose]

I’m a UK O2 customer just arrived in USA (Orlando). I have an iPhone 13.  I have international roaming option with O2. Network selection is on Automatic and AT&T is the network automatically selected. However I got the following text from AT&T:

”Welcome, you are roaming on AT&T. Due to network technology compatibility, traditional voice calls will not work. Please use data, SMS, and app-based calling.”

Data seems to work fine, but as the above text says, I can’t make standard phone calls.

What can I do to fix this?

[pgn · Accepted solution]

App-based calling means using FaceTime or WhatsApp - both you and your called party will need to have the same app installed for this to work. 

Also if you have working data connectivity, you may wish to manually select a different carrier, and see if they will offer normal voice calling as well. You may also benefit by switching your phone from 5G, if enabled, to 4G. Good luck, @ChrisRose.