Stop Tax Haven Abuse Act

[AI summary unavailable — showing source text] Stop Tax Haven Abuse Act - Authorizes the Secretary of the Treasury to impose restrictions on foreign jurisdictions or financial institutions operating in the United States that are of prime money laundering concern or that significantly impede U.S. tax enforcement. Amends the Internal Revenue Code to: (1) establish a rebuttable presumption against the validity of transactions by institutions that do not comply with reporting requirements under the Foreign Account Tax Compliance Act, (2) treat certain foreign corporations managed and controlled primarily in the United States as domestic corporations for tax purposes, (3) require tax withholding agents and financial institutions to report certain information about beneficial owners of foreign-owned financial accounts, (4) treat swap payments sent offshore as taxable U.S. source income, (5) allow the use of tax return information to evaluate foreign financial account reports, (6) increase penalties for promoting abusive tax shelters and for aiding and abetting the understatement of tax liability, (7) prohibit tax advisor contingent fee agreements for obtaining a tax savings or benefit, and (8) impose additional requirements for third…