Learn the history and meaning of usps postal codes, why it's called a ZIP code, whether a postal code is a ZIP code, and what ZIP code numbers stand for.

For some credit card purchases in Canada, a postal code is required as a security measure. If using a credit card in the U.S., you may need to use a ZIP code instead.

The House passed two bills Monday night that would authorize the U.S. Postal Service to create 76 new ZIP codes for communities nationwide.  These ...