Comment by ifwinterco

Switzerland does it and my understand is they basically just ask you to fill in a tax return every year and say how much wealth you have (all the assets you own).

Presumably they do have a department of people checking this to make sure people aren't lying, but also Switzerland is a relatively high trust society, and taxes are reasonable, so people probably don't mind paying too much.

In the UK in 2025 I'm not sure this would work, people would try and evade it and the UK government isn't competent enough to stop them