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
All states and U.S. territories
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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 62028 Elsah Jersey County 618, 636
IL 62030 Fidelity Jersey County 618
IL 62031 Fieldon Jersey County 217, 447, 618
IL 62032 Fillmore Montgomery County 217, 447, 618
IL 62033 Gillespie Macoupin County 217, 447, 618
IL 62034 Glen Carbon Madison County 618
IL 62035 Godfrey Madison County 618, 636
IL 62036 Golden Eagle Calhoun County 618, 636
IL 62037 Grafton Jersey County 618, 636
IL 62040 Granite City Madison County 618
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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.