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.

“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 ...

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.

Postmaster Arthur L. Jennings announced Saturday that Texarkana had been selected as a "Sectional Center" under the new ZIP ...