Additional numbers In 1983, a hyphen and four-digit code were added to some of the ZIP codes. The ZIP+4 code was implemented when it became difficult to sort mail based only on traditional ZIP ...

They are the five numbers that stand for home. Since 1963, ZIP codes have been a part of just about every piece of mail that travels through our system. But what do those numbers stand for?

You probably know your ZIP code by heart but do you know what it stands for? It turns out that the five or so digits point to some pretty specific information about you and where you live in the ...

ZIP codes were unveiled in 1962, but it was more than 20 years before the U.S. Postal Service announced nearly 100% compliance with the five-digit system.