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 60038 Palatine Cook County 224
IL 60039 Crystal Lake Mchenry County 815
IL 60040 Highwood Lake County 224, 847
IL 60041 Ingleside Lake County 224, 779, 815, 847
IL 60042 Island Lake McHenry County 224, 779, 815, 847
IL 60043 Kenilworth Cook County 224, 847
IL 60044 Lake Bluff Lake County 224, 847
IL 60045 Lake Forest Lake County 224, 847
IL 60046 Lake Villa Lake County 224, 847
IL 60047 Lake Zurich Lake 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.