The purpose of calling with a restricted cellphone number is to prevent identifying information about the caller from appearing to the recipient. A call placed using a restricted phone line prevents the caller's name and phone number from displaying. Restricted numbers protect privacy.
According to federal regulations enforced by the Federal Communications Commission (FCC), all states must provide the option of per call or per line blocking on landlines and most cellphone carriers also provide this service. To restrict the phone number from being revealed on an individual call, the caller dials *67 immediately before the 10-digit phone number.
If someone calls a company for any reason, the telephone number could be captured unless restricted. A company could use the telephone number in a variety of ways, including: making sales calls, matching against a database of names and addresses to mail advertisements or selling to direct marketing companies.
In some instances, a phone number will be displayed despite any restrictions. Calling numbers with the prefix of 800, 866, 877, 888 or 900 will allow capture of the phone number. Also, if a phone calls an emergency services line like 911 then all identifying caller information is displayed.
The FCC requires telemarketing companies to display accurate identifying information when making calls.