How do you find a location's nine-digit zip code?

The United States Postal Service has a zip code lookup tool on its website. Entering the street address, city, and state returns that location’s full 9-digit zip code.

On the USPS website, locate the drop-down menu named Quick Tools on the left side of the screen and click the down arrow. Select the option Look Up a Zip Code. Enter the known address information and click Find.

USPS also provides a tool to look up cities in specific zip codes. This option is accessible within the same zip code tool, accessed by selecting the tab named Cities by Zip Code at the top of the page.