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 62289 Summerfield St. Clair County 618
IL 62292 Tilden Randolph County 618
IL 62293 Trenton Clinton County 618
IL 62294 Troy Madison County 618
IL 62295 Valmeyer Monroe County 314, 557, 573, 618, 636
IL 62297 Walsh Randolph County 618
IL 62298 Waterloo Monroe County 618
IL 62301 Quincy Adams County 217, 447, 573
IL 62305 Quincy Adams County 217, 447, 573
IL 62306 Quincy Adams County 217
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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.