How is it legal for someone based in the US to setup a UK company to run his business? Isn't this a recipe to get the IRS to investigate this as a tax evasion scheme? I mean if it's possible, then every online business should incorporate in HongKong and avoid Taxes, VAT and several other complications that the IRS put.
It's legal as long as you report any income you make from it personally. There's nothing stopping you from incorporating in the Seychelles, and getting a bank account in Latvia, Belize, or Panama/St Vincent. Just so long as you report foreign income paid out to yourself. The foreign corporation doesn't have to report anything (this might have changed, i'm not a lawyer). That's why you see all those shady collector co…
additionally, he will need to file a TD 90-22.1 with the department of treasury by june 30th of the year after the account has more than USD 50K in it.
tax avoidance is a complex beast and simply incorporating a business in another jurisdiction does not in any way exempt you from US tax liability.