Fix Zip Code Diploma For Free

ZIP Codes? (5-digit or ZIP+4®) is required in the return address of all mail on which postage is paid with precanceled stamps or company permit imprint, and in the sender's return address on Periodicals mail when "Address Service Requested" is specified.

A ZIP+4 Code is a 4-digit code appended to a standard 5-digit ZIP that helps the USPS sort, route, and deliver mail more efficiently. The last 4 digits of these 9-digit ZIP Codes usually represent 6-20 delivery points on a USPS carrier route.

In 1983, the USPS expanded ZIP codes further by introducing the ZIP+4 system. This nine-digit system added four numbers to everyone's ZIP code, identifying the side of the street for an address or, in the case of some very large buildings, the part of the building where the addressee is located.

So what do the extra numbers mean? These last 4 digits represent specific delivery routes within delivery areas. This extra detail means an even more precise matching to a more granular level. It could represent a handful of houses on one side of a street, or even a single building that receives a high volume of mail.

United States ZIP codes are five numerical digits long. ZIP+4 codes, also known as add-on or plus-four codes, include four additional digits that identify a geographic segment within a ZIP code delivery area. The first digit in a ZIP code represents a defined group of U.S. states.

The USPS assigns ZIP Codes. All post offices are assigned at least one unique 5-digit ZIP Code. Larger post offices may be assigned two or more 5-digit ZIP Codes (multi-5-digit ZIP Code offices). Separate 5-digit ZIP Codes are assigned to each delivery unit at these offices.

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.