Many people ask us what is form 6166. In this article, We will answer their question.

Form 6166 is a letter printed on letterhead from the U.S. Department of the Treasury stating that the listed individuals or entities are residents of the United States within the meaning of United States income tax laws. You can use this form to claim income tax treaty benefits and other foreign tax benefits. See the instructions for Form 8802.

You can also use this form outside the USA, but it requires to apostille at first. Our website: usapostille.com provides it.

We provide attestation service for the US Tax Residency Certificate issued by the Internal Revenue Service (IRS), which is used in countries participating in The Hague Convention of Apostille. Because we receive an apostille of  US Tax Residency Certificate from the US Department of State in Washington DC, and we help businesses authenticate the form from the US Department of State and the embassy of the destination country in Washington DC.

If your documents will be used in a non-participating country in the Apostille Convention, legalization of the embassy is necessary to recognize them. You can order it from our site too.