telephone numbers with the prefix 555 are widely used for fictitious telephone numbers in north american television shows, films, video games, and other media, although real numbers do exist in this range. not all numbers that begin with 555 are fictional&mdash;for example, 555-1212 is one of the standard numbers for directory assistance throughout the united states and canada. in fact, only 555-0100 through 555-0199 are now specifically reserved for fictional use - except for the 800 area code where only 800-555-0199 is reserved - the other numbers have been released for actual assignment. the entire 555 exchange is reserved in all overlay north american toll-free area codes (844, 855, 866, 877, 888) and in canada's rarely used non-geographic area code 600. area code 555 in the north american numbering plan is reserved for directory assistance applications. == fictional usage ==  telephone companies began encouraging the producers of television shows and movies to use the 555 prefix for fictional telephone numbers by the 1960s. two early examples include the second time around (1961), which used 555-3485, and panic in year zero! (1962), which used 555-2106. "rossmore 555", mentioned in eyes in the night (1942), may be considered a precursor. in television shows made or set in the mid-1960s or earlier, "klondike 5" or "klamath 5" reflects the old convention for telephone exchange names. before "555" or "klondike-5" gained broad usage, and before mobile phones became commonplace, scriptwriters would sometimes invent fake exchanges starting with words like "quincy" or "zebra", as the letters "q" and "z" were not used on the old dial phones. numbers in format "zenith" x-xxxx, while not directly dialable, were not fictional. these were an early form of regional tollfree number which required operator assistance. 555 use is restricted only in north america. in the late 1980s, cartoonist gary larson's the far side included a panel with graffiti of a 555 number by which prank calls could be made to satan. in australia, 555 was at the time a standard exchange. the owner of the number became the subject of harassment, launching an unsuccessful lawsuit 
Cinema_of_the_United_States Fictional_telecom_protocols In-jokes North_American_Numbering_Plan Telephone_numbers