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?

Hanna Horvath is a CERTIFIED FINANCIAL PLANNER™ and Red Venture's senior editor of content partnerships. Fox Money is a personal finance hub featuring content generated by Credible Operations, Inc.

Richard Casey Sadler is a member of the American Association of Geographers. I write this as we approach the first anniversary of my involvement in the Flint Water Crisis, an ongoing catastrophe and ...