The intercom feature allows you to make an announcement to another extension without requiring the other party to pick up the handset. The message will be played via the other phone’s speaker. The audio is two way, and the called party can respond immediately without picking up the handset. To call a user via the intercom function:
Prefix the extension you wish to call with *9, followed by the extension. For example to make an intercom call to extension 100 you should dial: *9100
Important: Intercom is disabled by default for security reasons. If you want your phone to Auto-answer 3CX Make Call requests (when the phone does not support CTI like the Cisco SPA series) you need to configure a dial code in the 3CX Phone System Settings >> Advanced >> Dial Codes tab. This Dial code must be unique and must not conflict with any of the other dial codes.