Zip+4 isn’t specific enough either, you can still run into the same issue. Depending on area, that can be very rare. My building has its own zip+4, and even my

Zip+4 isn’t specific enough either, you can still run into the same issue. Depending on area, that can be very rare. My building has its own zip+4, and even my P.O. Box has its own. In wrangling voter data, I didn't hit a single case where a given zip+4 spanned multiple precints (but the 2000 census gerrymander came close in a few cases).