Utilizing the *67 service to block a phone number does not cost money. Phone service providers are required by the Federal Communications Commission (FCC) to provide customers with free methods to block and unblock their numbers on a case-by-case basis.
If someone has a blocked phone number and wants to display the phone number for a single call, dialing *82 before inputting the recipient's number permits the caller's information to be displayed. This is a free service that phone companies are required to offer.
Callers with blocked phone numbers who are calling emergency services or 1-800 numbers may have their numbers shown to the party that they are calling due to the technology used by these companies.