Why do I have to dial these numbers to disable carrier & select SIMBA as a carrier? February 17, 2023 07:22 Updated This is only for certain types of handsets where the VoLTE functionality is locked on the phone by default. Related articles What are the supported devices? How do I enable VoLTE? I could make calls when I was with my previous service provider. Why can’t I make calls now? What is the APN Setting for SIMBA? What is VoLTE?