Star 67 is a service code that allows you to hide your phone number when making a call. When you dial *67 before the number youre calling, it blocks the call youre making at that moment, not any future calls. This means that if you want your number blocked on every call, you would have to dial *67 before dialing out every time. However, if you want your caller ID information withheld on all your phone calls, youll need to block your number permanently by calling your wireless carrier. Its important to note that *67 only works to hide caller ID information on the phone call you use it for.