We will be updating the Zoom Phone platform to use a Trusted Public Certificate Authority. This change will take affect for users based in US East region/SIP zone on April 3, 2021.
Zoom Phone admins should ensure that they have updated their public certificates on their devices and carrier if needed. Zoom Phone users must be on Zoom desktop client or Zoom desktop app 5.0.5 or later for full functionality.
For more information and to see when this change will be implemented for other regions, please see: https://support.zoom.us/hc/en-us/articles/360056087612