US Zip+4 (the "long" zip code) is quite specific. I've never tried to address a letter using only e.g. addressee name and zip code but it would probably work.

US Zip+4 (the "long" zip code) is quite specific. I've never tried to address a letter using only e.g. addressee name and zip code but it would probably work. Closest thing I can think of are my tax returns which I address something like: IRS KANSAS CITY, MO xxxxx Some older US house numbers are just sequential (or incrementing) along a road but many are based on some "origin" point and increase by e.g. 100 for each standard city block. Usually even numbers on one side of the street and odd on the other. But there is no dependably consistent scheme from town to town AFAIK.