I can see from the Twilio Voice API Reference the OutgoingCallerIds resource enables programatic verification of Caller IDs with a voice call made to the user's phone.
The Twilio Console allows verification of Caller IDs via both voice and text so hoping: Is there a parameter to enable programatic verification via text as well?
Just had confirmation from a Twilio engineer that confirming via text is not possible. Twilio might be introducing text based confirmation of CallerID down the line though.
One work around our Twilio Account Manager offered is to approve us for any phone number and that we then introduce our own phone number validation which can of course include text based confirmation.
The onus would be on us to ensure we handle bad actors attempting phone number spoofing. We did not proceed down that route and just used call based validation.
