ss. At least, I think.
It is not required, no, but I'm not sure how much it speeds sorting up if it is present. I know that the barcodes used by the USPS to machine-sort mail contain only the ZIP+4 information (you find these barcodes on a lot of marketing-type mail; the stuff that gets sent out in bulk).
The ZIP code in general may be required, although as I understand it, it's *supposed* to be the same information as the city+state (like ZIP+4 is city+state+address), just in a form that's easier to automatically read and sort. If that's true, then mail should still get delivered without a ZIP, it will just take a lot longer. But it sounds like they had a ZIP, so it should be there.
Hmm... |
