So I figured out that if the call transfer doesn’t work, it’s most likely Shaken/Stir in Twilio (I confirmed by looking at Twilios call logs) Are you guys using your clients twilio for all of the phone numbers Or are you using your own twilio account? I can see either way working - but if can also see bottlenecks of using the clients twilio and if you want to text, having to do A2P registration and now STIR/ SHAKEN