From the customer view in https://admin.webex.com, go to Management > Locations.


Select the location where you would like to change the main number.


Select the Calling tab and choose the phone number from the drop-down menu under Main Number.


For extension-only users, this is the caller ID number. For PSTN calls, this number can be assigned to users or features.


If you choose a toll-free number as the main number for a location, we recommend updating the Emergency Callback Number for the location because a toll-free number does not have an emergency services address. For more information, see Configure Emergency Callback Number for a Location.


Click Save.