[craz8]

US zip codes are actually 10 characters, eg 90210-3356

These last 4 provide the resolution needed to avoid this confusion.

I too live in the Seattle area and have this same doppelgänger problem, so I use the full zip code when possible (not all web sites allow it, and the last mile delivery is by hand, so can still go wrong)

[SoftTalker]

I live in a neighborhood where houses are numbered by block, starting at "100" at the city center (many/most US address schemes work this way)

Due to being nearly the same distance east and north from the center point, there is a house around the corner that has the same address number as mine, theirs is "East" and mine is "North" and the street name is different. I don't know if we both have the same 10-digit zip code, but we do still get each other's mail at least a few times a month.