The Evolution of the ZIP Code
In 1983, the USPS realized that the standard 5-digit ZIP code wasn't granular enough for an ever-expanding population. Enter the ZIP+4 system. While the average citizen rarely memorizes those extra four digits, they are the secret weapon of bulk mailers and modern logistics companies.
Decoding the Plus Four
The standard 5 digits get a piece of mail to a specific post office. The "+4" digits take it much further. The first two numbers of the extended code usually pinpoint a specific delivery sector—like a group of streets, several blocks of a city, or a large cluster of office buildings. The final two digits narrow it down to a "delivery segment," which could be one side of a street, a specific floor in a skyscraper, or a single large corporate department.
Why It Saves Money
If you are a business sending out thousands of catalogs, including the ZIP+4 code saves the post office sorting time. In return, the USPS offers significant bulk mailing discounts. It also drastically reduces the chance of misdelivered mail, proving that sometimes, four little numbers make a massive financial difference.