FAQ: Troubleshoot incoming calls not getting recorded
Answer:
There are two possible reasons why you may receive an 'Invalid Phone Number' error when sending a text message:
The phone number is invalid.
You are sending a text message to a landline number.
To determine the type of phone number in your account, check the letter in front of the phone number. The letters indicate:
'V' - VoIP number
'M' - Mobile number
'L' - Landline number
'N/A' - the number is invalid.
Make sure you are not sending text messages to invalid or landline numbers.