The ZIP code system is an integral part of the United States Postal Service (USPS). ZIP is the abbreviation for “Zone Improvement Plan”. The ZIP code system divides the vast geographical area of the United States into systematically processed codes for efficient mail delivery.
As of October 19, there are approximately 41,702 ZIP Codes in the United States. To find out your ZIP code, you can use the online ZIP lookup tool.
ZIP codes are five-digit numerical codes that provide crucial details about the geographic location of the residents as well as specify the destination of the post office or the delivery area to which the mail or package will be sent for the final sorting and delivery. The United States has 2 well-functioning ZIP code systems: ZIP and ZIP+4.
Introduction of ZIP Codes by U.S. Postal Service
With one of the most advanced addressing systems in the world, the United States also has one of the intricate postal code systems—the ZIP code. The Zone Improvement Plan (ZIP) Code was established and pushed forward strongly by the Post Office Department in 1963.
The early use of the ZIP codes began with postal district/zone numbers. The United States Post Office Department (USPOD) later implemented it in many large cities in 1943. The USPS began fractionating bigger cities into delivery zones in 1943, and by 1963, the whole country had been divided into five-digit postal delivery codes. Mailers were required to adopt ZIP codes in 1967. The introduction of ZIP Codes reduced the number of incorrect deliveries and strengthened the postal delivery services.
Two Postal Code Systems: ZIP & ZIP+4
The standard ZIP codes in the United States comprise five numerical digits. The first digit of the code identifies the broad area, the next two digits denote the central post office in a specific location, and the last two digits represent the small post offices or delivery area.
The ZIP+4, also known as the “add-on codes”, “plus-four codes” were introduced by the United States Postal Service in the year 1983. A ZIP+4 code uses the standard five-digit code plus the four additional codes that designate a geographic segment within the five-digit delivery area like—city block, apartments, a post office, or any other unit that can benefit from the add-on codes through efficient mail sorting and delivery.
ZIP Codes Today
The ZIP code system of the United States today includes a ubiquitous physical delivery network with an extremely highly developed infrastructure, further accelerated by the national Addressing Management System (AMS).
The ZIP Code has stimulated new businesses, aided government services, and even modified towns as it has expanded beyond its original intended role as a mail delivery tool. Today, ZIP codes and mailing addresses are commonly acknowledged as an important feature of a person’s identification. They provide a foundation for social interaction and administrative coordination in addition to integrating individuals into the postal system.