Select My voicemail & phone features > Phone Features.
In the Outgoing Calls section, select Caller ID Blocking.
Select ON to enable Caller ID Blocking.
Select OFF to disable Caller ID Blocking.
Select Save.
Additional tips
If Caller ID Blocking is permanently enabled, you can allow your phone number to be displayed for just one call. Press *82, dial the number, then press #.
If Caller ID Blocking is permanently disabled, you can block you phone number from being displayed for just one call. Press *67, dial the number, then press #.