Many U.S. treaty partners require U.S. citizens and U.S. residents to provide a U.S. Residency Certificate in order to claim income tax treaty benefits, and/or certain other tax benefits, in those foreign countries. The IRS provides this residency certification on Form 6166, a letter of U.S. residency certification.
Form 6166 is a computer-generated letter printed on stationary bearing the U.S. Department of Treasury letterhead certifying that the individuals or entities listed are residents of the United States for purposes of the income tax laws of the United States.
To obtain Form 6166, a letter of U.S. Residency Certification, you must submit a completed Form 8802, Application for United States Residency Certification and pay a user fee if submitted after November 1, 2006.
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