Do I need a phone number to register?

In order for Sideline to give you perfect voice quality, the app uses radio towers to transmit voice signals (same as your phone carrier) to make calls. For this purpose, you will need to register a mobile phone number as a mandatory part of the account creation process.

Important: Only numbers from the Contiguous United States-based Carriers are accepted at this time.

If you don’t have a mobile number to use for registration, you may be interested in our other application, TextFree, which uses your email (or Single Sign-On such as Facebook, Apple, or Google) to register. 

Important:

• Sideline is designed to be used as a second number for your mobile device and relies on your mobile service for managing communications.
• For the most reliable service, we strongly recommend registering with a number from an active carrier plan.
• Using a Voice over Internet Protocol (VoIP) number is not guaranteed to function properly.
• Using a number not associated with your device will result in the inability to register for an account.
• Landline numbers are not supported for registration, as they are not connected with your mobile device.

If you have further questions, please submit a request.