Since I am pretty sure this is on a Mitel SX-200 ICP, I moved this topic here.
There are a several things that have to happen for Caller ID to be displayed on the console.
1) You must be receiving Caller ID on your trunks from your telco
2) They must be connected to a trunk port that supports CLASS service (not all trunk cards do, especially in older systems and older T-1 trunks)
3) The Class of Service and Trunk Attributes of the trunks must be configured to allow Caller ID
4) The Class of Service assigned to the console must contain the proper features to allow Caller ID to be displayed on the console.
So let's start with the simple questions... What kind of trunks do you have?