Where Is Area Code 312?
Area code 312 serves central Chicago, Illinois, in Cook County and the Great Lakes region of the United States. It is the city's traditional downtown code and covers the central part of Chicago rather than the entire city.
The 312 service area includes The Loop and nearby downtown districts. It lies along the Chicago River and near the western shore of Lake Michigan. The area code boundary follows telephone numbering assignments, not a separate city or county boundary.
Cities and Communities in the 312 Area Code
- Chicago, Cook County
- The Loop, Chicago, Cook County
History of Area Code 312
Area code 312 was one of the 86 original North American Numbering Plan area codes assigned in 1947. It originally covered Chicago and a wider surrounding area than it covers today.
In 1989, area code 708 was created from part of 312 to serve many Chicago suburbs. In 1996, area code 773 was created for most of Chicago outside the central area, leaving 312 focused on downtown Chicago. Area code 872 became an overlay for the 312 and 773 regions in 2009 as demand for telephone numbers increased.
Key Facts About Area Code 312
- Area code 312 is an Illinois area code, and Chicago is its primary city.
- Area code 312 is located in the Great Lakes region of the United States.
- Area code 312 is a geographic area code, not a toll-free code.
- Area code 312 is one of the original 86 North American Numbering Plan codes assigned in 1947.
- Area code 312 now focuses on central Chicago, including The Loop.
- Area code 773 serves much of Chicago outside the 312 area, while area code 872 overlays both the 312 and 773 regions.
- Willis Tower, at 233 South Wacker Drive, is a major Chicago landmark in the 312 area.
- The Art Institute of Chicago, at 111 South Michigan Avenue, is located in the 312 area.
- Chicago City Hall, at 121 North LaSalle Street, is located in the 312 area.
- Area code 312 uses Central Time.
Frequently Asked Questions
What state is area code 312 in?
Area code 312 is in Illinois.
What major cities use area code 312?
Chicago is the major city using area code 312, and the code is concentrated in central Chicago.
What time zone is area code 312 in?
Area code 312 is in Central Time.
Is area code 312 a toll-free number?
No. Area code 312 is a geographic area code, not a toll-free number.