The phone company can block a caller's name and phone number from appearing on calls made to phones equipped with caller ID. Caller ID blocking is available on a per line basis or per call.
Per-line blocking of caller information is provided free by all phone companies. The Federal Communication Commission requires each phone company to make this feature available free of charge.
To block caller ID information on a per-call basis, the dialer must enter *67 before each call. To block it on a per-line basis, the customer has to request the feature from the phone company. If per-line is enabled, *82 must be dialed before dialing a phone number to display the caller's information.