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
Maps and coordinates
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 61072 Rockton Winnebago County 608, 779, 815
IL 61073 Roscoe Winnebago County 779, 815
IL 61074 Savanna Carroll County 563, 779, 815
IL 61075 Scales Mound Jo Daviess County 608, 779, 815
IL 61077 Seward Winnebago County 779, 815
IL 61078 Shannon Carroll County 779, 815
IL 61079 Shirland Winnebago County 779, 815
IL 61080 South Beloit Winnebago County 608, 779, 815
IL 61081 Sterling Whiteside County 779, 815
IL 61084 Stillman Valley Ogle County 779, 815
Page 55 of 159

Geographic Map of Illinois

Postal context

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.