Withhold Caller Display allows you to block your identity when you're making a phone call. This feature is always off until you activate it. You activate this feature before you begin dialling.
You can activate Withhold Caller Display any time you make an outgoing call.
Withhold Caller Display allows you to make discreet calls. If the party you are trying to reach has Caller Display, your number will not appear on their Caller Display-enabled phone or device.