Caller ID blocks your mobile number from being displayed when placing a call. It is on a per-call basis and must be enabled before every call that you want to block your Caller ID for.
Caller ID Block
To block your Caller ID from being displayed when calling a specific mobile number:
1.Dial *67, followed by the 10-digit mobile number (including area code) that you are calling. (For example: *72-303-123-5555)
2. Tap Call