About Chicago: Counties: Cook County, DuPage County
Mayor: Rahm Emanuel
Area Codes: (312) (872) (773) (872)
Doing Business in Chicago? Here’s what you need to know. Business licenses can be obtained at the City of Chigago business affairs and consumer protection page, located at 121 N. LaSalle Street, 8th Floor, Chicago, IL 60602 or by calling 1.312.744.1944. They can also help with questions on city events, jobs, and information on construction permits and inspection.