Enhanced Caller ID lets you see the calling party's phone number when you are already on a call.
A special display device located on or next to your phone is required to allow you to view the calling number.
When you are already on the phone and you receive a call, the display screen will show you who is calling after you hear the first beep.
Note: Enhanced Caller ID requires a subscription to Call Waiting and Caller ID and a special display device compatible with Call Waiting.
See additional notes under Caller ID.