Before sending a recipient's first Verify SMS verification, you must obtain opt-in consent from the user to receive OTP messages. You must keep a record of this consent and be able to provide it to Twilio on request. For example, you could add a notice in the sign-up flow that indicates to the user that they are requesting OTP messages to be sent to their provided number and then record a timestamp of when the user completed the sign-up flow.
Verify SMS follows the Twilio Messaging Policy, please see the policy for more detailed information on consent and opt-in rules.
Verify Fraud Guard
: A feature that prevents SMS related fraud on Verify by automatically blocking the prefix of the destination of the suspected fraud.