The United States Postal Service provides a ZIP code look-up service where users can find ZIP codes for a particular address if they know the street name and city. Private websites with access to public information like UnitedStatesZipCodes.org and Zip-Codes.com also offer online code finders.
The U.S. Postal Service introduced ZIP codes in 1963 to improve mail service and make delivery more efficient. ZIP is an acronym that stands for Zone Improvement Plan. The postal service maintains a public database of every ZIP code in the country that is made available to many third-party websites. There are also websites that allow users to look up street and city information by plugging in a particular ZIP code.