All cell phones now come standard with a caller ID feature. Most landline phone services also have the caller ID feature available for a monthly fee. Caller ID raises privacy concerns for those who wish to remain anonymous when making a call, or for those who have an unlisted phone number. To protect the privacy rights of cell phone users, FCC rules make it mandatory for all cell phone companies to offer per-line, or per-call blocking and un-blocking features that are both simple and universal.
Find the contact in your phone. Go to your cell phone's address book and locate the phone number you wish to call anonymously. Record the number on paper. You will not be able to auto-dial the number from your phone contacts.
Dial 67 before you dial the contact's phone number. For example, to anonymously call 555-1212, simply dial 67555-1212 and push "Call" or "Send" to complete the call.
Dial 82 to make all future calls to a particular contact anonymous. Go to the call screen on your cell phone and dial 82 before dialing the contact's phone number. All calls you make to this number will now be anonymous. Use *82 again to unblock your number from this contact going forward.