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 work?

Most Americans know their ZIP code by heart. They type it into online forms, scribble it on envelopes and memorize it as part of their address. But not everyone knows the original meaning of the term.

Forbes contributors publish independent expert analyses and insights. I cover real estate, economics and cost of living. Dec 30, 2024, 10:40am EST Tribeca is located within the most expensive ZIP code ...