There is also another type of postal code, the ZIP + 4 code. According to unitedstateszipcodes.org, the ZIP + 4 was established in 1983 and identifies an even more specific location within a ZIP code.

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.

Removing the necessity of city and state on envelopes and packages, and leaving it to a formulaic five-digit zip code improved accuracy of mail sorting, and quite frankly, greatly improved the speed ...

“Or, if you are still not convinced, there are more than 32,000 5-digit ZIP codes in the United States; so 73,000 x 32,000 is more than 2 billion possible combinations but there are only 310 ...

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 ...

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 ...

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.

Norfolk, Va. – Effective immediately, anyone sending mail to Navy mobile units must use a nine-digit ZIP code to ensure delivery, according to a message released by Secretary of the Navy Ray Mabus.