Thanks fo the quick reply. Had a look at the link you provided. It looks like TPG only supports 3 of the Sony phones (Xperia X, Xperia Z3, Xperia Z5). As I mentioned in my original question I have a Xperia I II. The specifications for the phone says VoLTE is supported, but following instructions from Sony's web page there is not an option to enable VoLTE under the settings menu. There is an option to enable VoLTE in the dialer codes but it is disabled. The IMS service status screen indicates:    IMS registration: Not registered    Voice over LTE: Unavailable This seems to indicate that the profile for my phone is not enabled on the TPG network. I guess that I will have to look around for a solution Thanks again for the rely ... View more