ZIP Codes Finder

The ZIP code is the acronym for Zone Improvement Plan. A ZIP code system  is the system of postal codes used by the United States Postal Service (USPS). ZIP is always written properly in capital letters. These are written at the bottom of the mailing address. ZIP code makes sure that the mail travels more efficiently, and therefore more quickly, when senders use it. The format for the ZIP code is kept simple. The basic format consists of five numerical digits. ZIP Code was originally registered as a trademark by the U.S. Postal Service but its registration has since expired.

The United States Postal Service established ZIP (Zone Improvement Program) Codes in 1963 to help better distribute the growing amount of mail in the United States. The five-digit ZIP Codes begin with a digit from 0-9 that represents a region of the U.S. "0" represents the northeastern U.S. and "9" is used for the western states. Each subsequent digit of the ZIP code further refines the geographic area to help pinpoint the correct post office.

The first digit designated a broad geographical area of the United States, ranging from zero for the Northeast to nine for the far West. This was followed by two digits that more closely pinpointed population concentrations and those sectional centers accessible to common transportation networks. The final two digits designated small post offices or postal zones in larger zoned cities.