The first thing to try is to go to the UPS address validation tool, enter your address, and see what changes UPS suggests.
If your address still won't validate after making the changes suggested by UPS, there's a good chance it's for one of the following reasons:
- new construction
- address not registered with USPS
- addressed marked as "vacant" by USPS
So how do you fix this? You're going to want to contact the nearest USPS Address Management Systems branch, which you can lookup via this link. Once reported, it usually takes USPS 1-2 weeks to resolve most issues. In the meantime, you might try shipping to a neighbor with a valid address.