I registered a new mailing address with the USPS. They said it’d take a few days to show up in their zip+4 database. It’s been over a week and still showing invalid address. I’ll be charged for my po box eventually for having registered a physical mailing address.
Anyone know how long it should be before the lookup on zip+4 shows it?
A lot of companies use the USPS database to determine if an address is deliverable. A home under construction, for example, or one that is currently vacant will have valid addresses, but will be marked as 'non deliverable. So mail sent to them could be returned to sender when it his the USPS system.
And, technically, there’s the additional part of the zip code that no one ever talks about, the delivery point. A full zip code actually has 12 numerals, zip (5), +4 (4), delivery point (2), and a check digit.
I think this is it. There’s an official database that you can get that has all of the USPS recognized addresses. Several pieces of software that I’ve worked on will try to “validate” addresses entered by users against that database. If the address you mentioned isn’t in there, and can’t be reasonably matched to one that is in there, you get a big fat error message saying “unrecognized address” or something like that. After all, how do you know whether there is a 43545346236 New Sdaspdpmaspom-Uopmaposeipaw Street NE-by-ENE, Old East New Cecilstown Heights, Alaska 99999? Have you gone there to verify?
Address validators could do a decent job of putting addresses into the “standard” USPS form. So it could recognize e.g. “Parkersburg 44444” and recognize that officially, the part of Parkersburg that is in zip code 44444 is officially designated as East Parkersburg and make the address say “East Parkersburg 44444”.