With 50 US states, plus territories, and the thousand cities and municipalities, it's no surprise that finding the right postal code can be a pain. The USPS (United States Postal Service) even changes their ZIP code list on a regular monthly basis, which adds more complication to the process.
Luckily, a little know-how can help save you some stress over the question “what is my postal code?” Learn more by reading about US ZIP codes here.
Define A ZIP Code
A ZIP (Zone Improvement Plan) Code is a coding system used by the Post Office to efficiently facilitate the sorting and delivery of mails. The basic 5-figure format was initiated in 1963, before an expanded, 9-figure version was introduced in 1983. The updated ZIP code, also called a ZIP+4 Code, consists of an additional 4 numbers added to the base 5 digits with a hyphen (e.g. 20500-0001, the personal ZIP code of the US President).
The ZIP code you need depends on location, but it is important to note that USPS doesn't assign ZIP codes according to state lines. In fact, different states can have the same codes. And although codes can be a rough geographic approximate of a territory, it should not be used as a marker for such.
This is because the Post Office functions according to delivery routes, instead of territorial boundaries. They assign codes according to their available resource, hence why some locations do not have a postal code. This is also the reason why ZIP codes are regularly updated, to account for the new openings and closures of local post offices.
Types of ZIP Codes
Location and delivery routes aren't the only identifiers for assigning postal codes. USPS factors in different variables in their decisions, leading to a few types of ZIP codes. Getting familiar with the types of existing postal codes will help you find out which one suits your needs most.
1) Standard/Normal ZIP Codes
These are codes that majority of the population will use, with either the basic 5 numbers or the +4 version.
2) PO Box ZIP Codes
Post Office Boxes have their own ZIP+4 Codes as a general rule. These boxes exist in multiple locations, but are more specifically for areas that are not within USPS delivery routes.
3) Military ZIP Codes
Military personnel don't always have a physical address to receive their packages at. Instead, they have their corresponding ZIP codes to serve this purpose.
4) High-Profile/High-Volume ZIP codes
These postal codes are dedicated to people or entities that are either prolific or receive a constant, large number of mails and packages. An obvious example is the US President, while a more infamous owner of a personal ZIP code includes Santa Claus.
To write Santa a letter, simply address it to 99705. It will then be sent to an Alaskan town called North Pole.
Find Your Postal Code
USPS keeps an updated record all postal code changes they make. Of course, they are the most reliable source for this information.
For those of us who do not want to bother going through the hoops of government websites, there are plenty of online ZIP code trackers for our perusal.