Federal document
IRS Form 6166 Certification of US Tax Residency
How to apostille IRS Form 6166, the U.S. residency certification used to claim tax-treaty benefits and open accounts abroad.
- Issuing agency
- Internal Revenue Service
- We can obtain it?
- No — you request it from the agency
- Certification first?
- No prior certification needed
- Also known as
- tax residency certificate, certificate of residency, Form 8802 result
IRS Form 6166 is a letter from the Internal Revenue Service certifying that you or your company are a U.S. resident for tax purposes. Foreign tax authorities and banks require it to grant tax-treaty benefits, reduce withholding, or open accounts. To be accepted overseas, it usually needs an apostille.
Why it needs an apostille abroad
A U.S. tax-residency letter means little to a foreign authority without proof it is genuine. The apostille certifies the IRS document for use across Hague Convention countries; non-Hague destinations require embassy legalization.
How to get IRS Form 6166 for use overseas
Getting the form first
Form 6166 is requested from the IRS using Form 8802 — a step you complete directly with the IRS, often weeks in advance. Once you have the 6166 letter in hand, send it to us and we take it through apostille. We cannot request it from the IRS on your behalf, but we will tell you exactly what to file.
Common uses
- Claiming tax-treaty benefits to avoid double taxation.
- Reducing foreign withholding tax on income or dividends.
- Opening foreign bank and brokerage accounts.
IRS Form 6166 apostille by country
Where the document is going decides the process. Hague Convention members accept an apostille; non-Hague countries need embassy legalization on top. Pick your destination:
Ready to start?
Tell us what you have and where it is going. We reply with the correct route, a flat quote and shipping instructions.