Locations for Area Code - 312

Area code 312 serves the central core of Chicago, Illinois, including the downtown Loop and major business districts. As one of the original area codes created in 1947, 312 once covered all of northern Illinois but now represents a highly concentrated urban zone. Overlays with 872 have made ten-digit dialing necessary. Chicago's economic, cultural, and political significance is closely tied to the prestige of the 312 area code, which continues to be associated with legacy institutions, iconic architecture, finance, and national media. It is one of the most recognizable and desirable area codes in the Midwest.