60421: Unexpected result when creating contact

Twilio returns this error when Verify cannot create the contact record needed for your request. Verify uses the destination you send in to to start a verification for a phone number or email address, and that value must be valid for the channel you selected. For phone-based channels, the destination must be in E.164 format. For email, any channelConfiguration.from value you include must be a valid email address.

• The request body contains contact information that Verify cannot use to create the contact, such as a malformed phone number or email address.
• For SMS, voice, WhatsApp, or Silent Network Auth, the to value is not formatted in E.164.
• For the email channel, channelConfiguration.from is included but is not a valid email address.
• The API request is sent with an unsupported content type instead of application/x-www-form-urlencoded or multipart/form-data, which can cause unexpected API errors.
• A user entered the wrong phone number or email address during sign-up or profile update, and the incorrect identifier was sent to Verify.

• Validate the contact data before you send the request. For initial verification flows, show the full phone number or email address back to the user so they can catch typos before you start verification.
• Normalize phone numbers to E.164 before calling Verify. For example, use +14155552671 instead of a local or partially formatted number.
• If you use the email channel, confirm that the Verify Service is configured for email and that any channelConfiguration.from value is a valid email address.
• Send the request using application/x-www-form-urlencoded or multipart/form-data. If possible, use an official Twilio helper library to avoid request formatting issues.
• Retry the request only after you correct the contact information in the request body.

• Start a verification
• Send Email Verifications with Verify and Twilio SendGrid
• Verification and two-factor authentication best practices