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 60694 Chicago 312
Cook County IL 60695 Chicago 312
Cook County IL 60696 Chicago 312
Cook County IL 60697 Chicago 312
Cook County IL 60699 Chicago 708, 773, 312, 872
Cook County IL 60701 Chicago 312, 224
Cook County IL 60706 Harwood Heights 464, 708, 773, 872
Cook County IL 60707 Elmwood Park 464, 708, 773, 872
Cook County IL 60712 Lincolnwood 224, 773, 847, 872
Cook County IL 60714 Niles 224, 773, 847, 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.