I was just booking a flight and hotel accommodation for an upcoming work trip, and it occurred to me: why does everyone ask for the state and the ZIP code, when the state can be derived from the ZIP code?
For example, 94043. The first three digits fall within 900 to 961, so it's obviously in California.
It seems like such an annoying extra step to have to drop down a list and find your state. At least I'm in one close to the top.
I guess I could ask the same question about Australia. The state is similarly encoded in the post code.
Any system I ever have anything to do with in the future is not going to ask for the state.