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IRS Form 6166 Apostille

Updated: Nov 8, 2022

What is Form 6166 - Certification of U.S. Tax Residency?

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.

IRS Form 6166 Sample
Form 6166 Sample

How to obtain IRS Form 6166?

To obtain Form 6166, a letter of U.S. Residency Certification, you must submit a completed Form 8802, Application for United States Residency Certification. A user fee is charged to process all Forms 8802. More details can be found on the IRS website.

We cannot obtain IRS Form 6166 on your behalf, and you'll need to apply by yourself. Here is a detailed guide on how to apply for IRS Form 6166 and other information.

Apostille Process of IRS Form 6166

IRS Form 6166 is a federally-issued document that must be apostilled or authenticated by the U.S. Department of State in D.C.

If your document will be used in the Hague Convention Countries, order the Apostille service below.

If your document will be used in Non-Hague Convention Countries, order the multi-step authentication service below.

Simply place the order based on your situation and mail us the original copy you received from the IRS. We will contact the right people and department at the U.S. Department of State to apostille your Form 6166 or authenticate it at the U.S. Department of State and then get it legalized at your destination country's embassy.

Mailing Address:

American Notary Service Center

7512 Diplomat Drive, Suite 101,

Manassas, VA 20109

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