Did you recently receive an error message that states: "Make sure you've entered a valid phone number and try again" but you believe that you are sending a message to a valid phone number?
First, make sure you're attempting to send to a supported country. Sideline supports messages to numbers with +1 (North America) and + 5 (South America) country codes.
For a full list of supported countries, you can send text messages to, click here
Other instances in which you may receive this error message:
- The intended recipient is a landline number
- The intended recipient is a short code (verification number)
If you have questions about the information above or are still experiencing difficulty sending a message, please submit a request.