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 61299 Rock Island Rock Island County 309
IL 61301 La Salle LaSalle County 779, 815
IL 61310 Amboy Lee County 779, 815
IL 61311 Ancona Livingston County 779, 815
IL 61312 Arlington Bureau County 779, 815
IL 61313 Blackstone Livingston County 779, 815
IL 61314 Buda Bureau County 309, 779, 815
IL 61315 Bureau Bureau County 779, 815
IL 61316 Cedar Point LaSalle County 779, 815
IL 61317 Cherry Bureau County 779, 815
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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.