U.S. postal lookup

U.S. ZIP Codes Database 2026

Search by ZIP code, city, county, or state and find clear postal details with maps, time zones, and area code data.

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Cook County ZIP Codes

Browse all ZIP Codes, cities, and associated area codes registered in Cook County.

County State ZIP Code City Area Codes
Cook County IL 60643 Chicago 464, 708, 773, 872
Cook County IL 60644 Chicago 464, 708, 773, 872
Cook County IL 60645 Chicago 224, 773, 847, 872
Cook County IL 60646 Chicago 224, 773, 847, 872
Cook County IL 60647 Chicago 773, 872
Cook County IL 60649 Chicago 773, 872
Cook County IL 60651 Chicago 464, 708, 773, 872
Cook County IL 60652 Chicago 464, 708, 773, 872
Cook County IL 60653 Chicago 312, 773, 872
Cook County IL 60654 Chicago 312, 872
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About U.S. ZIP Codes

ZIP codes are a United States Postal Service system introduced in 1963 to make mail routing more accurate and efficient. The standard format uses five digits, while ZIP+4 adds four more digits for a more precise delivery segment.

ZIP codes cover the United States, its territories, military mail routes, and other USPS delivery points. This directory organizes that data for practical lookup by ZIP code, city, county, and state.