Issue
You may encounter an "Invalid Address" error (code 51001) when attempting to configure a WhatsApp number for auto-creation of conversations using Twilio's API. This error typically arises when there is an issue with the address format or configuration.
Product
Twilio Conversations API
Cause
The error code 51001 indicates that the address format or configuration is incorrect. In some cases, this error occurs when using a "Whatsapp Business Number" with a 555 area code is used. These type of numbers are not compatible with Twilio as these numbers do not have a real phone number behind them.
Resolution
Whatsapp Business Numbers are not supported by Twilio. Customers will need to have a Whatsapp number configured to a telephone number.