### Answer
Currently, Vapi directly supports phone number integration with Twilio and Vonage. If you have a phone number from a different provider, Vapi's current documentation does not specify a method for integrating other external phone providers directly. You would typically need to use either Twilio or Vonage to work seamlessly with Vapi services.
For more detailed guidance on phone number integration and capabilities with supported providers, you can refer to the official documentation on phone calling and importing numbers from Twilio or Vonage [(1)](
) [(2)](
) .