We are writing to inform you of an immediate change that impacts SMS functionality in the RingCentral Developer Sandbox environment.
Due to recent updates in carrier regulations, all Sandbox numbers associated with free developer accounts have been disabled for SMS effective immediately.
If SMS is needed for development purposes, you will need to purchase a paid RingCentral account and complete the carrier required SMS registration through the RingCentral Admin Portal.
We know this change may impact application development, and are dedicated to working with you to help you build and deploy your application inline with industry regulations.
Thank you for your understanding,
RingCentral Developers Team