Choose Zip Code Certificate For Free

There are four primary types of ZIP codes: PO Box, Unique, Military, and Standard.

In short, unique ZIP codes are high volume mail receivers that receive mail at one location and then distribute the mail internally. Unique ZIP codes generally are used by large organizations, government buildings, universities or large medical facilities.

A 5-Digit ZIP code represents a USPS delivery area. A 9-Digit ZIP code, also known as a ZIP+4 code or an extended ZIP code, includes the same information as the 5-Digit ZIP code, plus additional information about a specific delivery route within the delivery area.

A United States postal code, for example, might be either five digits or five digits followed a hyphen (dash) and another four digits (12345-1234). If you are validating US postal codes, allow for both conditions. The following rule validates a field that can be five digits, five digits + dash + 4 digits, or blank.

Primary state prefixes. ZIP Codes are numbered with the first digit representing a certain group of U.S. states, the second and third digits together representing a region in that group (or perhaps a large city) and the fourth and fifth digits representing a group of delivery addresses within that region.

ZIP codes are numbered with the first number representing a certain group of U.S. states. The second and third numbers represent a region in that group of states or, in some cases, a large city. The fourth and fifth numbers representing a group of delivery addresses within that region.

Also called ?plus-four codes?, ?add-on codes?, or ?add-ons?, the ZIP+4 code starts with the standard five-digit ZIP Code. The four extra numbers are added after a hyphen to complete the ZIP+4. So what do the extra numbers mean? These last 4 digits represent specific delivery routes within delivery areas.