Let’s put it clear: that U.S. guy is an idiot and he is risking serious consequences for just a few hundred $ rebates.
If a U.S. person helps structure transactions, moves funds, or provides advice that results in transferring proceeds of foreign tax evasion through the U.S., he is inside the money laundering statute even if the actual taxes are owed abroad. This can simply mean using USD currency.
18 U.S.C. § 1956 criminalizes financial transactions designed to conceal proceeds of specified unlawful activity. Specified unlawful activity includes foreign tax crimes when the foreign country criminalizes them. This was defined by the PATRIOT Act (2001) expansion of the definition.
See for example United States v. Kazzaz, 592 F. App’x 608 (9th Cir. 2014), which upheld money laundering charges based on foreign tax evasion as the predicate.
But there’s more.
18 U.S.C. § 1343: Wire Fraud
If the U.S. person communicates electronically with clients abroad while knowing the plan involves illegal evasion of a foreign tax regime, DOJ can stretch wire fraud theories. They usually combine it with money laundering for extra slaughtering.
18 U.S.C. § 371 + §1956: “Conspiracy to commit money laundering”
This is your one way ticket to jail. If he merely gives advice but knows clients will funnel funds into or through the U.S., risk becomes extreme. DOJ does not care that the tax loss is suffered by a foreign state.
In short: the U.S. does not prosecute foreign tax evasion itself, but it prosecutes conduct inside U.S. jurisdiction that facilitates foreign tax evasion, usually via money laundering or wire fraud.
