Alton IA ZIP Code
Alton city is located in Iowa State, Sioux County and has a unique zip code assigned by the US Postal Service Office.
You can search for the Alton IA zip code by its streets and block numbers if we have some of the Alton streets loaded in our website
Alton Area Code is 712 and Time Zone is Central (GMT -06:00).
Alton Zip Code - Iowa
The US ZIP Code basic format consists of five decimal numerical digits assigned to the Alton City. An extended ZIP+4 code, introduced in the 1980s, includes the five digits of the Alton ZIP code, a hyphen, and four more digits that determine a more specific location within a given ZIP code in Alton, Iowa.
The Alton Zip Code is 51003.
If you want to send a mail to Alton City, you should use the 51003 Zip Code.
In 1983, the U.S. Postal Service introduced an expanded Alton 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 51003 Zip code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a Alton 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 Iowa.