Twilio asks users to verify their existing phone numbers or caller IDs before making any new outbound call. 

This is how you can add a verified phone number or caller ID on Twilio:

  1. Log in to your Twilio account at https://www.twilio.com/log
  1. Select your country zone from the drop-down menu and enter your ten digit phone number. Twilio will then call you to confirm your number. 
  1. Tap “Call me.” Moreover, you can opt for text mode to verify your number. 

That’s it, you are good to go!