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Error 21211

ERROR - 21211

Invalid 'To' Phone Number

You attempted to initiate an outbound phone call or message, but the Called phone number you supplied was not a valid phone 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. You attempted to initiate an outbound phone call, but the To phone number you supplied was not a valid phone number.

Possible Causes

The formatting of the 'To' number you supplied was invalid.

Possible Solutions

Twilio accepts phone numbers in E164 format: [+] [country code] [subscriber number including area code]

You can find a full list of country codes for phone numbers on this Wikipedia page.

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