13223: Dial: Invalid phone number format

Phone Numbers must be in E.164 format. E.164 numbers are formatted [+] [country code] [subscriber number including area code] and can have a maximum of 15 digits.

• The phone number you are attempting to dial is not in E.164 format
• The <Number> noun inside your <Dial> TwiML instructions is not present
• You are attempting to dial something that is not a phone number

Check the format of the phone number inside your <Dial><Number> TwiML.

Verify that the number is in E.164 format:

• Includes the country code
• Includes the area code
• Does not exceed 15 digits
• Does not include any invalid characters, like hyphens or parentheses

In your TwiML instructions, the phone number must be between the opening and closing <Number> tags, which are nested within <Dial>'s opening and closing tags:

<Dial><Number>+15555555555</Number></Dial>

If you are attempting to <Dial> an SDK end-user, ensure you're using the <Client> noun inside your <Dial> tags.

If you are attempting to <Dial> a SIP endpoint, ensure you're using the <Sip> noun inside your <Dial> tags.

For more information, read the <Dial> docs.