ZIP Code Boundaries Data#
ZIP Code Boundaries represents five-digit ZIP Code areas used by the U.S. Postal Service (USPS) to o assist in the efficient sorting and routing of mail. The first digit of a five-digit ZIP Code divides the United States into 10 large groups of states (or equivalent areas) numbered from 0 in the Northeast to 9 in the far West.
Within these areas, each state is divided into smaller geographical areas, identified by the second and third digits. These digits, in conjunction with the first digit, represent a Sectional Center Facility (SCF) or a mail processing facility area. The fourth and fifth digits identify a post office, station, branch or local delivery area.