When creating a label, USPS verifies that the Ship From and Ship To addresses are valid addresses. If they can't find a match in their address database, they won't let you buy that label.
In either case, we recommend doing two things:
1) Use the USPS address lookup tool to:
- Use the "Find Cities by ZIP" tool to make sure the city name you're using is the correct one for that zipcode.
- Then use the "Find by Address" tool to see if the address is a valid address.
2) Use Google Maps to see if there is actually a house/building at that address, and if the address should be formatted in a different way.
What if the address is a brand new street / building / neighborhood / development?
In this case you actually need to tell USPS to add the address to their database. Use this form to determine which USPS office to contact to get the new address added: https://ribbs.usps.gov/locators/find-ams.cfm