Some post offices service more than one zip code but, for much of the U.S., there's a one-to-one ratio of post offices to zip codes. The second two numbers of a zip code specify a specific region within that geographic area and the last two are meant to indicate a specific Post Office. The first number, between 0-9, denotes a geographic area of the U.S. Most frequently, your five digit zip code represents the destination of the post office your mail is sent to before being handed off to your mail carrier.Įach number of a zip code corresponds to a specific piece of information about the destination. more efficient by dividing the country up into zones based on mail routes. When zip codes were first introduced in 1963, it was a part of an initiative to make mail delivery in the U.S. Postal Service (USPS) since the beginning. This is the norm for most people and has actually been the norm for the U.S. When someone asks for your zip code, you probably reply with a string of five numbers.
So, what exactly is the deal with those extra zip code numbers? We've got the answers.
You may have seen these when receiving a package that was addressed automatically or you might have seen this zip code as a suggestion when ordering something online. One of the most frequent errors in writing out an address relates to the zip code - particularly the four extra zip code numbers sometimes found at the end of your address.
#Us zip code range how to#
In the age of emails, DMs and video calls, you might not be overly familiar with traditional mail, and you may not even know how to properly write out your address.