You can set up to twelve numbers to ring when someone calls your line using the Simultaneous Ring feature. If any one of the lines answers a call (including your line), the other phones stop ringing. If no one answers the call, the caller returns to your office phone's voicemail.
To turn on Simultaneous Ring:
Did you know? You can turn Simultaneous Ring on and off using the Simultaneous Ring icon (a blue circle with a white phone) on the toolbar.