
Form 6166 and Form 8802: How U.S. Residents Cut Foreign Withholding by Certifying Tax Residency
Form 6166 is the IRS letter that lets U.S. taxpayers claim treaty rates on foreign royalties, dividends, and services. This guide walks through the Form 8802 application, eligibility rules, common rejection traps, and the timing required to get withholding right at the source.



