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What are Unique Zip Codes

What Are Unique Zip Codes?

ZIP code is the term coined by the USPS for the postal code system in the United States. The term ZIP stands for “Zone Improvement Plan.” A ZIP code is a set of numbers that conveys information about people in various geographical groups. In the United States, there are two ZIP code systems: ZIP and ZIP+4. For the ZIP-code system, which was introduced in 1963, the basic format consists of 5 digits. The ZIP+4 code system, introduced two decades later, includes the five digits of the original ZIP code followed by a hyphen and four extra digits. The four extra digits in the ZIP+4 code system help identify a geographical segment within a ZIP code delivery area. In the United States, ZIP code data is an essential component of corporate operations. It’s a crucial parameter for delivering mail, handling fraud detection, and gathering demographic data. This article will talk about the four types of ZIP codes and focus on unique ZIP codes.

What are Unique ZIP Codes

USPS has a classification system for ZIP codes which can be broken down into four types, each with its own indicator. This classification system helps the USPS sort mail more quickly and deliver it more efficiently. The first type is the Standard ZIP code which is the most widely used type of ZIP code. The Standard ZIP code is indicated by an “S.” The second type is a PO Box-Only ZIP code. A PO Box-Only ZIP code is used for addresses requiring access to postal services, but mail delivery from the USPS is impossible. A “P indicates the PO Box-Only ZIP code.” The third type is a Military ZIP code. Military bases overseas, such as vessels or ships, use this ZIP code. An “M indicates the Military ZIP code.” The fourth type is a Unique ZIP code. A “U indicates unique ZIP codes.” Unique ZIP Codes are special ZIP Codes given by the United States Postal Service to addresses that receive a high volume of mail. The types of organizations include government agencies, major corporations, or universities. The USPS delivers all of the mail at a single location at the institution. These organizations are large and most likely have an internal postal distribution system. The responsibility of the USPS to deliver the mail ends once it has dropped off the mail at the location. It is then the institution’s responsibility to deliver the mail to the intended parties accordingly. 


To sum it all up, there are four different types of ZIP codes classified by the USPS. The Standard ZIP code, indicated by an “S”; The PO Box-Only ZIP code, indicated by a “P”; The Military ZIP code, indicated by an “M,” and lastly, the Unique ZIP code, which a “U indicates.” The Unique ZIP code is used for addresses with a high volume of incoming mail. Unique ZIP code holders usually consist of extensive medical facilities, government agencies, or universities. Mail at these institutions is typically delivered to a specific site and then distributed internally to the necessary parties.


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Written by Austin Proctor 


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