ZIP codes are simply a collection of postal codes accessed and managed by the US Postal Service (USPS). They’ve been used since 1953 to help the USPS manage mail and packages more effectively when it comes to ensuring that everyone gets their mail sent to the right places. Interestingly, the term ZIP was used for two reasons. The first reason is that ZIP stands for “Zone Improvement Plan”. The second reason was that the word Zip seems “quick”, so it makes people think that their mail is traveling more efficiently when it’s zipping between locations.

When you look at a ZIP code list online, you’ll find that most options include five digits, but there was a ZIP +4 system introduced within 1983, which helps to further organize mail according to the specific locations where it should be delivered. Originally, the term ZIP code was trademarked by the USPS, but over the years, the company’s claim on this term has expired.

How are ZIP Code Lists Chosen?

When it comes to understanding the ZIP code lists you see online, the first thing you need to know is that the first digit of your ZIP code will typically represent a group of states in America. The map you can get online of the first digit of zip codes shows that the numbers are assigned starting from the north-east side of America, and moving along to the western coast. The first three digits in a code will determine which processing office mail and packages should be sent to.

When the post office needs to organize mail, it’s sent to a sectional, or sec center, which helps to determine where each piece of mail needs to be delivered. Any mail with the same 3 initial digits will be delivered o the same sec center, where it’s later distributed according to the remaining two digits at the end of the ZIP code number. As you can see from maps of ZIP codes, the second lot of digits for ZIP codes are also assigned from the east of the country through to the west.

Importantly, if you want to send mail across America, then you don’t necessarily need to use the +4 digits for your ZIP code. However, using these numbers can make it easier to sort mail in the post office. These codes generally correspond with information about a group of apartments, or a city block, or a single person who generally receives a large amount of mail. Typically, each PO Box number available will have its own ZIP+4 coding too. This means that if you’re looking for a very specific area with a ZIP code list, then you might get a +4 code instead of a standard five-digit code.

How do ZIP Code Boundaries Work?

Many people who look for a postal ZIP code list assume that these codes are generally geographic in nature. However, the truth is that ZIP codes are simply a way of grouping mail so that it can be delivered around the country in the most efficient manner possible. Some codes can span across various states to make it easier for the mailman to deliver mail.

Generally, addresses that are located close to one another will share the same ZIP code. This means that many people assume that ZIP codes can be identified by looking at certain geographic boundaries. However, many ZIP codes will have no connection to geographic areas at all. One example is the fact that there is a single code used for any time someone wants to send mail to the Navy.

Even when you believe that a ZIP code list shows a connection between areas and their ZIP codes, it’s hard to draw clear boundaries around the zip code. This is because each code is assigned simply to a single point of delivery. In areas that don’t have a lot of mail delivery, there may be no ZIP code whatsoever, or the ZIP codes available might not have clear boundaries attached to them.

Using Your Postal ZIP Code List

Ultimately, the best way to understand ZIP codes is to remember that they were designed to make it easier for people to deliver mail. These codes were not intended to correspond with boundaries like counties, states, and cities. In the case where it might be more efficient for carriers to move through state lines to deliver mail, ZIP codes will simply cross the state lines without any problem.

Understanding a ZIP code list can become even more complex when it comes to understanding how each code works within a specific county. According to statistics, around a quarter of all ZIP codes cross through county lines, which can make it harder for standard people to understand the way that ZIP codes are organized.

The good news is that you don’t necessarily have to understand how ZIP codes work, or how they are assigned by the USPS if you want to look up an address of someone that you don’t know with nothing but a small amount of ZIP code knowledge.

Sending Mail Without The ZIP Code:

A postal ZIP code list makes it easy to send mail without much knowledge about the address you want to send it to. If you’ve ever found yourself in a situation where you’d like to send a parcel or letter to an address in the US and you don’t know what the zip code is, then don’t worry. There are plenty of ways that you can find ZIP codes online for every address throughout the United States, and most of the ZIP code list services online are free to use too.

To access the system, you can simply search for information about an address by looking through cities, or if you remember the first number in the ZIP code then you can start your search here too. Some lists will allow you to find the full address of an individual or business simply by giving the name of a person or an organization, though it is helpful if you know something about the address at hand.