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 60558 Western Springs Cook County 331, 464, 630, 708
IL 60559 Westmont DuPage County 331, 630
IL 60560 Yorkville Kendall County 331, 630, 779, 815
IL 60561 Darien DuPage County 331, 630
IL 60563 Naperville DuPage County 331, 630
IL 60564 Naperville Will County 331, 630, 779, 815
IL 60565 Naperville DuPage County 331, 630
IL 60566 Naperville Dupage County 630
IL 60567 Naperville Dupage County 630
IL 60568 Aurora Kane County 630
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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.