A recent piece in The Guardian argues that South Dakota and other US states are actually becoming the go-to place to store anonymously your illicit cash and make sure that your heirs can inherit it without taxes forever:
https://www.theguardian.com/world/2019/nov/14/the-great-amer...Partly because the US has compelled other countries to provide more transparency without joining that transparency organization itself.
"Congress responded with the Financial Assets Tax Compliance Act (Fatca), forcing foreign financial institutions to tell the US government about any American-owned assets on their books. Department of Justice investigations were savage: UBS paid a $780m fine, and its rival Credit Suisse paid $2.6bn, while Wegelin, Switzerland’s oldest bank, collapsed altogether under the strain. The amount of US-owned money in the country plunged, with Credit Suisse losing 85% of its American customers.
The rest of the world, inspired by this example, created a global agreement called the Common Reporting Standard (CRS). Under CRS, countries agreed to exchange information on the assets of each other’s citizens kept in each other’s banks. The tax-evading appeal of places like Jersey, the Bahamas and Liechtenstein evaporated almost immediately, since you could no longer hide your wealth there.
How was a rich person to protect his wealth from the government in this scary new transparent world? Fortunately, there was a loophole. CRS had been created by lots of countries together, and they all committed to telling each other their financial secrets. But the US was not part of CRS, and its own system – Fatca – only gathers information from foreign countries; it does not send information back to them. This loophole was unintentional, but vast: keep your money in Switzerland, and the world knows about it; put it in the US and, if you were clever about it, no one need ever find out. The US was on its way to becoming a truly world-class tax haven."