AT&T VoLTE (HD Voice) on US997 jason531 Posted on 2019-02-11 18:23:32 G6 Vote Up0Vote Down

Has anyone gotten VoLTE/HD Voice working on AT&T with an unlocked US997?  My specific model is the LGUS997.  There are conflicting reports in various forums about how to get it working.  I can confirm it did work with Verizon Prepaid, but with an AT&T SIM the menu option to enable HD Voice is hidden from settings.  

One person on Reddit claimed he was able to get it working by getting a tech at AT&T to add the IMEI to some AT&T database of phones which support HD Voice/VoLTE.  Also, supposedly the Amazon Prime version of this phone, which I can only imagine has different firmware. not hardware, is reported to support HD Voice and WiFi calling on AT&T.

I need to know where to start.  If AT&T can fix it, I'll pursue that option.  However, if it is something on the firmware side where LG turns off the option when an AT&T SIM is detected then I need to see if there is some other firmware I can use, even if it means flashing the Amazon Prime firmware and dealing with the ads or paying to remove them.  I bought three of these phones and cannot just throw them away, but at the same time they are severely crippled without HD Voice.