top of page

Apostille Service for IRS Form 6166 to be used in Greece

Form 6166 is from the U.S. Department of Treasury used as proof to foreign governments that U.S. residents are eligible to receive tax treaty benefits. The United States has negotiated tax treaties with numerous countries worldwide that can help U.S. residents and companies who do business abroad. Reduced tax rates, exemption from double taxation, and other significant benefits can apply to various forms of international income, including subscriptions, research payments, licensing/royalties, etc.

Below are the steps for the Apostille of the IRS Form 6166.

Step 1. Go to to apply for an IRS Form 6166 - United States Residency Certification

For detailed instructions, click here.

This is what you will get from the IRS👇. It's a physical letter printed on U.S. Department of Treasury stationery certifying that the individuals or entities listed are residents of the United States for purposes of the income tax laws of the United States.

Step 2. Order the Apostille Service online

  • Fees: $186.00 per personal document or $236.00 per business document

  • Processing Time: 11 weeks (estimated, cannot be expedited, does not include the mailing time)

  • 💰 Total cost: $186.00 or $236.00 + Shipping

* We ship domestically and internationally but clients should be responsible for the shipping costs. You may choose the shipping method at the check-out page.

Step 3. Mail the document

Please mail us the original IRS form(s) you received from the U.S. Department of the Treasury. Photocopies are not accepted.

📮 Mailing Address

American Notary Service Center

7512 Diplomat Drive, Suite 101,

Manassas, VA 20109

You are all set!

Simply place the order 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.

The apostille and authentication process can be complicated. If you don't want to spend a lot of time and energy getting into it, your best bet is to let a professional do it for you. Once we receive your order and document, it'll be processed as soon as possible.

Besides IRS Form 6166, we also provide apostille, authentication, and embassy legalization services for other personal documents and corporate documents issued in 50 states and DC.


American Notary Service Center Inc. provides fair, fast, confidential, and professional document notarization and certification services for our clients. We also provide various assistance services to small businesses led by socially and economically disadvantaged groups. Our service helps small businesses obtain federal government contracts, gain a foothold in the market, and boost their sales. For more information, please visit our website at, and contact us by calling 202-599-0777 or by email at


bottom of page