[maxerickson]

Your first paragraph is largely true for the US (people running quite small businesses don't necessarily have to keep up with pay as you earn, but the limits are a few thousand dollars and then the correct thing is to make regular payments during the year).

[jarcane]

The difference is that US agencies don't actually use this information, likely because of privacy regulations and stop forth. The right hand rarely knows what the left is doing, unless law enforcement or homeland security get involved.

You can see this even more starkly in the difference between the two in regards to medical records. Or even just basic personal details. My Kela card mostly tells doctors all they need to know, and even my address changes seem to get around without my having to do anything about it.

It was a bit unsettling at first for an American, but the systems here are largely pretty efficient except where unemployment is concerned...