Monmouth IL ZIP Code
Monmouth city is located in Illinois State, Warren County and has a unique zip code assigned by the US Postal Service Office.
You can search for the Monmouth IL zip code by its streets and block numbers if we have some of the Monmouth streets loaded in our website
Monmouth Area Code is 309 and Time Zone is Central (GMT -06:00).
Monmouth Zip Code - Illinois
The US ZIP Code basic format consists of five decimal numerical digits assigned to the Monmouth City. An extended ZIP+4 code, introduced in the 1980s, includes the five digits of the Monmouth ZIP code, a hyphen, and four more digits that determine a more specific location within a given ZIP code in Monmouth, Illinois.
The Monmouth Zip Code is 61462.
If you want to send a mail to Monmouth City, you should use the 61462 Zip Code.
In 1983, the U.S. Postal Service introduced an expanded Monmouth ZIP code system that it called ZIP+4, often called "plus-four codes", "add-on codes", or "add ons". A ZIP+4 code uses the basic 61462 Zip code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a Monmouth city block, a group of apartments, an individual high-volume receiver of mail or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery in Illinois.