alt Hacker NewsA ZIP+4 does not encode all information.
Proof: a post office has its own zip code, for PO Boxes.
The +4 is the last four digits of the post office box.
If the Post Office has more than 10,000 boxes, the +4 will be duplicated.
A ZIP+4 does not encode all information.
Proof: a post office has its own zip code, for PO Boxes.
The +4 is the last four digits of the post office box.
If the Post Office has more than 10,000 boxes, the +4 will be duplicated.
Yeah, anyone who has had to work with USPS bar codes should know that internally these are called routing codes, and they come in 5, 9 and even 11 digit variants. The 11-digit one narrows down to a specific delivery point, but even that isn’t enough to derive an address (just enough to know whether you’re looking at the right one or not). Zip+4 codes also change frequently because they aren’t based on locations but on delivery routes and sequencing.