ZIP Code — A system of 5-digit codes that identifies the individual Post Office or metropolitan area delivery station associated with an address. ZIP+4 is an enhanced code consisting of the 5-digit ZIP Code and four additional digits that identify a specific range of delivery addresses.
ZIP+4 Code —A nine-digit numeric code composed of two parts: (a) the initial code: the first five digits that identify the sectional center facility and delivery area associated with the address, followed by a hyphen; and (b) the four-digit expanded code: the first two additional digits designate the sector (a geographic area) and the last two digits designate the segment (a building, floor, etc.).
ZIP+4 barcode —A nine-digit POSTNET barcode consisting of 52 vertical bars. Also see Postal Numeric Encoding Technique (POSTNET).
Zone Chart —The USPS Official National Zone Chart Data Program is administered from the National Customer Support Center (NCSC) in Memphis, TN. Single-page zone charts for originating mail are available at no cost from local Post Offices or online at pe.usps.com.
Zoned Price —A price structure for Priority Mail Express, Priority Mail, Periodicals, Standard Post, and Bound Printed Matter that is based on weight and distance traveled (or number of zones crossed).