TV & Movie Phone Exchanges - Ever wonder why phone numbers in TV shows and movies always start with a 555 prefix? Well, producers discovered that if they used a real phone number, thousands of curious viewers would dial the number.. So the phone company established the nonexistent 555 exchange.  The general 555 prefix is an established feature used in movies and television shows. It was designed to prevents people from receiving crank calls when a phone was mentioned on a TV show or movie. Fictitious numbers for Movies and TV  use 555-0100 to 555-0199.  You will also note that there are some numbers using prefixes such as GRAMARCY, PLAZA or KLONDIKE which do not conform to the 555 Prefix configuration. These prefixes reflect the exchanges-many from the 1950s-used before the common 555 prefixes were established.