[WBrentWilliams]

Ehh... US-centric. Better to use significance order: Country, then postal (most countries have postal), then region, city, and street address. Best, however, is to _not_ separate the address into fields. Instead, allow a free text field for the person doing data entry to put in the address in _their_ format and then parse it on the backend. This gets you the most flexibility and allows you to encounter and handle corner cases by using (my favorite test data) public addresses from all over the world. _I_ routinely test my address entry by Googling McDonald's locations and feeding them into my system. Handle an inscrutable address like any other bad data and say, politely, that your system does not understand the data.

All that said, free-form entry is a hard sell. My _customers_ expect field data entry, so I implement field data entry. I just re-order my checks to be more forgiving until the data entry is complete.

I was implementing a customer service address entry using significance order 25 years ago. As I already _knew_ that I had a US-centric customer base (we sold long distance to sorority and fraternity members), entering US ZIP first saved a lot of time and more highly leveraged the US postal address cleaner that we had already purchased for our mass marketing mailers. The people working the call center _loved_ it, as they could focus more on their call turn-over than on data entry.