Error 21401
ERROR - 21401
Invalid Phone Number
The phone number you specified was not a valid North American (US or Canadian) number. Twilio accepts only 10 digit US domestic and Canadian phone numbers, with or without a leading "1" or "+1", with any combination of character separators. For example, these are all valid: 415-867-5309, 4158675309, +1 (415) 867 5309. ## Error - 21401
Invalid Phone Number
The phone number you specified was not a valid SMS-enabled phone number or alphanumeric sender ID.
If a phone number was used, this number must be one you have purchased from or ported to Twilio in E.164 format.
Alphanumeric sender IDs can only be used with accepted characters when messaging countries where this feature is supported.
Possible Causes
The phone number is not supported in North America.
Possible Solutions
Try using a different phone number: https://www.twilio.com/phone-numbers