Question: My son is insisting that I can send him postcards to his name and 9-digit ZIP code, with no street address included. I don’t believe him. What’s the story and how do ZIP+4 ZIP codes ...

Almost everyone knows their five digit ZIP code, and probably a few others within their city, but what’s up with the extra four digits you sometimes see on mail? Let’s start with those first ...

A postal code is a five digit code used to help postal services deliver mail and packages. Here's what the numbers mean and how they determine yours.