ZIP+4 Code is an extra four-digit identifier added to the standard five-digit USPS Zip code. It is a great way to ensure that your mail is delivered correctly and accurately.

The ZIP+4 Code was introduced in 1983, as the United States Postal Service (USPS) was trying to accommodate an increased population. The ZIP+4 Code adds a fourth digit to the basic five-digit ZIP code and helps identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail or a post office box.
Having the correct ZIP+4 code is essential for shipping and labeling direct mail. The additional identifier can help reduce lost and misdelivered mail, qualify you for bulk mailing discounts, and speed up your mail sorting and delivery process.
How to Determine a ZIP+4 Code
The first column is the USPS-provided name associated with an address, such as a business or government building. The second column is the ZIP+4 code for the address. If there is a secondary address line, this is also used to determine the correct ZIP+4 code.
If you have a large database of addresses, it can be quite time-consuming to manually look up and validate the correct ZIP+4 code for each and every one of them. With the right address validation software, this process becomes a lot more automated and you can avoid having to spend countless staff working hours on it.