Why do phone numbers in TV shows and movies all start with 555?

Cecil replies:

Believe it or not, there are a few pinheads out there with nothing better to do than sit down and call every number they see on a television show or in a movie. “Hello, is Kojak there?” they say, chuckling at the sublimity of their wit. Generally, Kojak is not there, which causes a great deal of inconvenience for the poor sap who is. In one case several years ago a Peanuts strip carried a number that turned out to belong to a family in Moline, Illinois. Over 50 calls, ranging from plaintive requests to speak to Snoopy to less plaintive requests of a considerably darker nature, were logged in one evening.

Up until a few years ago, the phone company maintained a service that provided fictional (i.e., unused) numbers to producers and writers. But it soon developed, in this wide, wonderful country of ours, that there wasn’t a single number that wasn’t in use somewhere. The “555” gambit was created in 1973–no matter where you are, dialing the 555 number plugs you into directory assistance, where a legion of professionally trained operators awaits to answer the particular crankiness of your call. 555 isn’t an FCC regulation, but simply a convenient creation of Ma Bell.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.