What is Zip code / Postal Code

zip code is a system of postal codes used by the United States Postal Service (USPS). It stands for “Zone Improvement Plan” and was first introduced in 1963 to improve mail delivery efficiency. A zip code consists of a series of numbers that are used to identify a specific geographic location, such as a city or town, within the United States. The code is usually five digits long, but can be extended to nine digits for more precise location identification. Postal codes are used to help sort and deliver mail to its intended destination more efficiently.

What is the differences between zip codes and postal codes?

people seems to be confused of this two words, but the truth is that they serve as the same purpose. The only different is that zip code is mainly used in the US while postcode or postal codes are used in other countries. Mind you, not all countries uses zip codes or postal codes.

Zip codes/ postal code format in some countries:
USA: CA 90026 = somewhere in Los Angeles, California
UK: NW2 1QA = somewhere in northwest London, UK
China: 999077 = official postcode for Hong Kong
Japan: 103 = somewhere in Tokyo, Japan

There are four types of ZIP Codes:

Types of Zip Codes

  1. Unique address: Big organisations like Hospitals, universities, Government agencies and businesses that receives a lot of mails uses unique zip codes.
  2. PO Box only
  3. Military
  4. Standard (all other ZIP codes).

Uses of Zip codes/Postal codes

Zip code is very important in top world countries like the United states, Canada, United Kingdom and almost in every Country of the world, zip code is very important in sending mail, delivery/ logistics fraud detection and research demographic decentralization. Below are some major uses of zip/ postal codes:


  1. Delivery services: used for internal routing of a package.
  2. Mail delivery: Zip codes are used by the United States Postal Service (USPS) to efficiently sort and deliver mail to its intended destination.
  3. Census data: Zip codes are used by the United States Census Bureau to collect demographic and socioeconomic data about specific geographic areas.
  4. Marketing and advertising: Zip codes are often used by businesses and marketers to target specific areas for advertising and promotional campaigns.
  5. Emergency services: Zip codes can help emergency services, such as police and fire departments, to quickly locate and respond to calls for service in a specific area.
  6. Online transactions: Some online retailers and service providers use zip codes to verify the location of a customer’s billing address for security purposes.
  7. Statistics: For example, in the United State, there are over 42000 zip codes. Apart from delivery mails, zip codes are also used in gathering statistics.
  8. Internet purposes: You will often find zip code under most education or eCommerce website registration page.

Related Topics

How Do ZIP Codes Work?

ZIP codes work as a system of postal codes used by the United States Postal Service (USPS) to sort and deliver mail more efficiently. Here’s how they work:

The USPS divides the United States into 10 regions, each of which is assigned a number from 0 to 9.

Each region is further divided into smaller areas called Sectional Center Facilities (SCFs). Each SCF is responsible for sorting and processing mail for a specific geographic area.

Within each SCF, there are smaller areas called delivery areas or carrier routes, which are typically identified by a unique three-digit code called a ZIP code prefix.

The final two digits of a ZIP code represent a more specific geographic location, such as a city or town, within the delivery area.

In some cases, a ZIP code can be further extended to include a four-digit code, known as a ZIP+4 code, which provides an even more precise location identification.

When mail is sent to a specific address, it is first sorted by the SCF responsible for that area, then by the delivery area or carrier route, and finally by the specific address based on the ZIP code.

Overall, ZIP codes play a critical role in helping the USPS to sort and deliver mail more efficiently by organizing geographic areas into specific delivery routes.

Countries that dont make use of zip codes

There are several countries that don’t use zip codes or an equivalent postal code system. Here are a few examples:

Ireland: Ireland does not have a postal code system, although Dublin is divided into postal districts for sorting mail.

Jamaica: Jamaica does not use zip codes, but uses a postal code system called the Postal Code System of Jamaica.

Bahrain: Bahrain does not use zip codes, but uses a system of post office boxes for mailing addresses.

Malta: Malta does not use zip codes, but uses a system of postcodes for sorting and delivering mail.

Myanmar: Myanmar does not have a postal code system, although some larger cities may use a system of township codes for addressing mail.

It’s worth noting that while some countries may not have a specific zip code system, they may still have other methods of organizing and delivering mail.

Read also: Full List of Lagos State Postal Codes for Every LGAs

History of five-digit ZIP Codes

The history of the five-digit ZIP code system in the United States dates back to the early 1960s. Prior to this system, the post office relied on manual sorting and delivery, which was slow and inefficient.

In 1943, the Postal Service implemented a three-digit zone system for large cities, which helped to speed up mail delivery. However, this system was limited in its scope and did not cover all areas of the country.

In the early 1960s, the Post Office Department began a study of how to improve mail delivery times and efficiency. As a result of this study, the five-digit ZIP code system was developed and launched in 1963.

The first digit of the ZIP code represented a region of the country, with the numbers increasing from east to west. The second and third digits represented a sectional center facility within that region, while the final two digits represented the local post office or delivery area.

The new ZIP code system allowed for more efficient sorting and delivery of mail, and it also enabled businesses and organizations to use direct mail campaigns targeted to specific geographic areas. In the 1980s, the system was expanded to include the ZIP+4 code, which added an additional four digits to the original five-digit code to provide even more specific location information.

Today, the five-digit ZIP code system is an integral part of the U.S. postal system and is used by businesses, individuals, and government agencies for mail delivery and other purposes.

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