Why can’t I use the Three way calling / multi-conference call function? Why does it say “Unable to conference calls” when I use conference call function?
The Three way calling / multi-conference call function requires network/SIM card support. If your SIM card isn’t activated to provide these functions by your service provider, the device will show a “Unable to conference calls” message if you try to use it. Please contact your service provider to enable multi-conference call service for your SIM card.