How to Find the 4 Digit Zip Code Extension for a Specific ...
Enter the mailing address in the appropriate boxes and click "Find." For example, enter 1600 Pennsylvania Ave NW, Washington, DC if you are looking up the ZIP Code+4 Extension for the White House. In the search results, you will see the complete nine-digit extension is 20500-0003.
DA: 49 PA: 3 MOZ Rank: 74