Area code 773
Area code 773 serves Chicago, Illinois, outside the downtown area. It went into effect on October 12, 1996, with a grace period that ended on January 11, 1997. The area code covers the city, excluding the downtown area and adjacent neighborhoods.
Originally, all of Chicago and its suburbs were in area code 312. Then, in 1989, area code 708 was created for the inner-ring suburbs, leaving the city itself in area code 312. On August 10, 2007, the Illinois Commerce Commission announced that area code 872 would overlay area codes 312 and 773; it went into service on November 7, 2009.
The Illinois side of the Chicago area–312/773/872, 708, 847/224, 630/331 and portions of 815/779–is one of the largest local calling areas in the United States, but in-state long-distance charges are applied to calls to numbers over 15 miles away within the metro area. For example, a call from the Rogers Park exchange 338-XXXX on the north side to a Pullman Exchange 785-XXXX on the south side is billed as a long-distance call, even though both neighborhoods are within city limits.
