A postal code is a five digit code used to deliver mail and packages. There is also another type of postal code, the ZIP + 4 code. According to unitedstateszipcodes.org, the ZIP + 4 was established in ...

After the 5-digit ZIP code gets the mail to your local post office, the "plus 4" code gets it to your neighborhood. "Do you have to write it on your letters?" asked WCCO reporter Jason DeRusha.

The 54915 ZIP code can indicate Calumet and Outagamie counties, which have a 0.5% sales tax, but also Winnebago County, which doesn't have the tax.

The idea of a five-digit ZIP Code alone wasn't enough-it would be useless without a high adoption rate. And Day had been warned: executives at AT&T noted the difficulty they had in getting the ...

Over the next two decades the ZIP system became strained, too, and in 1983, the Postal Service expanded it to create the ZIP+4 system, tacking on an extra four digits at the end of the old codes.