A standard US ZIP Code has 5 digits, which directs mail to a specific post office. A ZIP+4 Code includes a hyphen and four additional digits (e.g., 12345-6789).

These extra four digits identify a highly specific delivery route, such as a particular city block, a group of apartments, or a high-volume business. Using the full 9-digit code ensures faster and more accurate delivery.

New Subdivisions and Developments

If you recently moved into a newly built home or a brand-new neighborhood, the address may not immediately appear in the national directory. Local municipalities must first register the address, and the postal service must officially add it to their Address Management System (AMS).

This process can sometimes take a few weeks. If you are experiencing persistent issues, you may need to contact your local post office to ensure the route has been officially established.

Yes. While small towns typically share a single 5-digit ZIP Code, large metropolitan areas are divided into dozens of different postal zones to handle massive volumes of mail.

If you are shipping to a large city, it is highly recommended to use the Search by Address tool above to find the exact code for that specific street, rather than guessing based on the city name.