Area code 224 is an overlay of 847 and serves Chicago’s northern suburbs, including cities such as Evanston, Arlington Heights, and Waukegan. Introduced in 2002, it was implemented to address increasing demand for numbers in one of the state’s most affluent and densely populated suburban regions. Ten-digit dialing is required. Area code 224 is linked to business, healthcare, and upper-middle-class residential areas, often associated with stability, suburban comfort, and proximity to Chicago's economic power.