The History of a Zip Code in Brief: Regular, ZIP-4, Etc.

A ZIP Code was created by the United States Postal Service (USPS). It’s also called postal code in other countries. The idea was implemented in 1963, not so long ago, unlike what a lot of people think. It has two types introduced in different years due to the increase in correspondence. The topic is very interesting and there’s a lot of information, so here we have a brief guide into the history of the code.

The Essentials

The term means the Zone Improvement Plan. It was introduced to make sure all correspondence travels right to its location. It was the USPS service mark until 1997. The new idea was heavily promoted to let all citizens know there are changes in how they should send letters. The main character for the promotional campaign was the so-called Mr. Zip.

The postal zones have been around in large cities since 1943. Every zone had its own number and was the basis for the future codes. In the 60s, the abbreviations for the states were also implemented, ranging from 2 to 5 letters (NB (later NE) for Nebraska or Calif. for California).

In 1971, the White House also adopted a code.

ZIP and ZIP+4

The initial version consisted of 5 digits:

• The 1st digit represents a united group of several states;
• The 2nd and 3rd numerals are used to identify a large city or a group of cities/towns in the region;
• The 4th and 5th identified the set of addresses for the delivery.

The following information is the precise address.

Oftentimes, the capital of the state or another large city gets the codes first, but usually, every city is assigned to one in alphabetical order.

ZIP+4 and IM

In 1983, a new system called ZIP+4 was implemented. It contained the same 5 digits plus an additional set of 4 digits assigned to a specific area in a city.

The implementation wasn’t a total success, so now, you don’t necessarily need the additional code to have your letter delivered. If you need yours, though, just use the ZIP+4 lookup.

There’s also another version called an Intelligent Mail code. Your usual ZIP code is translated to that version by the post office and printed on the letter. It’s necessary for the machines to be able to sort correspondence more easily and precisely.

The sender can do it themselves, but it’s not recommended since the databases they can find online might be outdated. It’s better to let professionals at the post office do it.

To Sum Up

Area codes might be quite confusing when you start getting into history. It’s a difficult thing to create a system that would identify regions properly. If you aren’t sure what your code is or which one to put in the address line, it’s better to go to the post office and ask a professional for help. This ensures your letter goes out to a proper location.