Why is my phone number "invalid" during verification?

The AirTime monetization system currently requires phone verification for every participant (viewer). 

Phone verification is a reasonably effective protection measure against abuse (e.g. bots). We block certain operators including VoIP providers to protect against fake phone numbers. Nevertheless, the service does sometimes throw false positives or "invalid phone number" responses for perfectly legitimate phone numbers. We are actively looking to improve this process. We apologize for the inconvenience.

If you are getting a "phone number is invalid" response, please contact our Help Desk for manual verification. Thank you.