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 62232 Caseyville St. Clair County 618
IL 62233 Chester Randolph County 573, 618
IL 62234 Collinsville Madison County 618
IL 62236 Columbia Monroe County 314, 557, 618
IL 62237 Coulterville Randolph County 618
IL 62238 Cutler Perry County 618
IL 62239 Dupo St. Clair County 618
IL 62240 East Carondelet St. Clair County 314, 557, 618
IL 62241 Ellis Grove Randolph County 573, 618
IL 62242 Evansville Randolph 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.