[Kon-Peki]

> the USPS... offer free access to an API that includes address validation, and thankfully most shipping services now use it.

Unfortunately not all. My street "number", like 100,000 other houses near me, includes a letter in the middle. USPS will happily validate it correctly, but there are still websites I encounter from time to time that complain or refuse to work.

Where I am, 100 years ago, if your house wasn't inside a city, it simply didn't have an address. The fire departments got together and created a geographic encoding scheme that would allow them to find a house if they needed to. In the 1960s, the USPS adopted it as official. New homes continue to be issued addresses according to the scheme, even though it is not rural at all - it's inside one of the largest metro areas of the US.

[illirik]

If you don't mind, which metro area is this? I have an interest in street grids and address numbering systems; this just sounded like a peculiarity I'd like to read up on.

[Kon-Peki]

Based on your recent comments, it’s right in your own backyard! Formerly and currently unincorporated DuPage and Kane counties. It seems that you have to build a new street inside an established municipality for those houses to get “normal” addresses.

FYI, I went to college in the 90s with a kid that lived in a rural area in a very low population county in Indiana (one stop light in the entire county). His house still had the old rural route addressing (your address was the box where you received mail - potentially miles away - and not a street address as commonly understood https://pe.usps.com/text/pub28/28c2_021.htm).