Definitions for "zip code"
Keywords:  usps, postal, nine, freight, delivery
any one of a set of numbers assigned by the United States Postal Service to designate a particular postal delivery area. One or more zip codes are assigned to each post office. The numbers initially had five digits (the initial code), indicating state and post office. Later, four more optional digits were added (the expanded code) indicating the box number or delivery route. The full set of nine digits is also referred to as zip + 4. The code is appended in an address to the line bearing the city and state names, as in "Plainfield, NJ 07062".
A ZIP (Zone Improvement Plan) Code is a five-, seven-, nine-, or eleven-digit code assigned by the U.S. Postal Service to a section of a street, a collection of streets, an establishment, structure, or group of post office boxes, for the delivery of mail.
Administrative units established by the United Postal Service (USPS) for the distribution of mail. ZIP Codes serve addresses for the most efficient delivery of mail, and therefore do not respect political or census statistical boundaries. ZIP Codes are identified by five digit codes assigned by the USPS. The first three digits identify a major city or sectional distribution center, and the last two digits generally signify a specific post office's delivery area or point.