U.S. POSTAL CODE DIRECTORY

Every U.S. ZIP Code.
One simple search.

Find ZIP Codes by city, state, county, or number. Explore location details with a clean, easy-to-use directory.

✓ Browse by state✓ Search cities & counties✓ Explore ZIP+4 information
Directory coverage 42,735 ZIP Code records

Illinois Zip Codes



Illinois Illinois is the 25th most extensive and the 5th most populous of the 50 United States, and is often noted as a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal, timber, and petroleum in the south, Illinois has a broad economic base. Illinois is a major transportation hub. The Port of Chicago connects the state to other global ports from the Great Lakes, via the Saint Lawrence Seaway, to the Atlantic Ocean; as well as the Great Lakes to the Mississippi River, via the Illinois River. For decades, O Hare International Airport has ranked as one of the world s busiest airports. Illinois has long had a reputation as a bellwether both in social and cultural terms and politics.

State Zip Code City County Area Codes
IL 60437 Kinsman Grundy County 779, 815
IL 60438 Lansing Cook County 464, 708
IL 60439 Lemont Cook County 331, 464, 630, 708, 779, 815
IL 60440 Bolingbrook Will County 331, 630, 779, 815
IL 60441 Lockport Will County 331, 464, 630, 708, 779, 815
IL 60442 Manhattan Will County 464, 708, 779, 815
IL 60443 Matteson Cook County 464, 708
IL 60444 Mazon Grundy County 779, 815
IL 60445 Midlothian Cook County 464, 708
IL 60446 Romeoville Will County 331, 630, 779, 815
Page 23 from 159

Map of Illinois

ZIP codes are a system of postal codes used by the United States Postal Service (USPS) since 1963. The term ZIP, an acronym for Zone Improvement Plan, is properly written in capital letters and was chosen to suggest that the mail travels more efficiently, and therefore more quickly, when senders use the code in the postal address. The basic format consists of five decimal numerical digits. An extended ZIP+4 code, introduced in the 1980s, includes the five digits of the ZIP code, a hyphen, and four more digits that determine a more precise location than the ZIP code alone. The term ZIP code was originally registered as a servicemark (a type of trademark) by the U.S. Postal Service, but its registration has since expired.

ZIP codes designate only delivery points within the United States and its dependencies, as well as locations of its armed forces. There are no ZIP codes reserved for designating mail bound for foreign destinations (with the exception of U.S. military units stationed outside of the United States), and therefore, international outbound mail should not include a ZIP code in the delivery address. The last line of a foreign address must only show the name of the country of destination.

Useful Websites: US Zip Codes