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.

42,735 verified records
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State directory

Illinois ZIP Codes

Complete postal directory, details, and geographic map for the State of Illinois.

State ZIP Code City County Area Codes
IL 60012 Crystal Lake McHenry County 779, 815
IL 60013 Cary McHenry County 224, 779, 815, 847
IL 60014 Crystal Lake McHenry County 224, 779, 815, 847
IL 60015 Deerfield Lake County 224, 847
IL 60016 Des Plaines Cook County 224, 847
IL 60017 Des Plaines Cook County 224
IL 60018 Des Plaines Cook County 224, 331, 630, 773, 847, 872
IL 60019 Des Plaines Cook County 224
IL 60020 Fox Lake Lake County 224, 779, 815, 847
IL 60021 Fox River Grove McHenry County 224, 847
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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.