A ZIP Code is a system of postal codes used by the United States Postal Service (USPS) to route mail more efficiently. It is a five-digit numeric code that identifies a collection of mailing addresses within the United States and its territories to simplify the distribution of mail. The basic format of a ZIP Code consists of five digits, and it was introduced on July 1, 1963. In 1983, an extended ZIP+4 code was introduced, which added an additional four digits after a dash to form a ZIP+4 code. The additional four digits help USPS more precisely group mail for delivery.
ZIP Codes are not created for statistical analysis, thus use for statistical analysis is heavily criticized for numerous reasons and advised against as a cartographic practice. Despite the fact that ZIP Codes seem to be geographic in nature, that wasnt their intended purpose. They are lists of addresses for delivering the mail, and they are not areas. However, many ZIP Codes have delivery areas, and some ZIP Codes are for buildings or campuses that have defined borders.
To find a specific ZIP Code, one can use the ZIP Code Lookup tool on the USPS website. The tool allows users to enter a corporate or residential street address, city, and state to see a specific ZIP Code, or enter a ZIP Code to see the cities it covers. ZIP Code data is also used by many websites for dealer/store locator software, which processes a user-input ZIP Code and returns a list of store or business locations, usually in the order of increasing distance from the center of the input ZIP Code.
