How to Get a U.S. Tax Residency Certificate (IRS Form 6166) in 2026: Form 8802, Fees, Timing and Apostille

November 3, 2026 · DC Mobile Notary™ — Washington, DC

Quick answer

A U.S. Tax Residency Certificate is IRS Form 6166, a letter on U.S. Department of the Treasury letterhead certifying that you are a U.S. resident for federal tax purposes. Foreign tax offices ask for it before they apply a tax treaty rate or grant certain other tax benefits, such as a VAT exemption.

To get one, file Form 8802, Application for United States Residency Certification, and pay the IRS user fee: $105 for individuals or $230 for businesses and other entities for applications postmarked on or after October 1, 2026. The IRS asks you to apply at least 45 days before you need the certificate.

If the foreign office also wants an apostille, only the U.S. Department of State can issue it, because Form 6166 is a federal document. DC Mobile Notary™ handles that step in 9 business days. Call 202-247-0837.

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Form 6166 at a glance (2026)

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What a U.S. Tax Residency Certificate looks like

Form 6166 is a computer-generated letter on Department of the Treasury letterhead from the IRS in Philadelphia. It names the taxpayer, the taxpayer identification number, the tax year and the treaty country, and carries a facsimile signature of the Field Director of the IRS Philadelphia Accounts Management Center. The key sentence certifies that, to the best of the IRS's knowledge, the taxpayer is a resident of the United States for purposes of that country's tax treaty with the U.S.

Each certificate covers one tax year and one country. See the annotated sample on our Form 6166 apostille page.

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Who can get Form 6166, and who usually can't

The IRS generally issues Form 6166 when it can confirm, usually from a filed return, that you were a U.S. resident for tax purposes in the year you need certified. That covers U.S. citizens and resident individuals, corporations, S corporations, trusts, estates, exempt organizations and employee benefit plans. Partnerships, LLCs taxed as partnerships and disregarded entities can apply too, but the certification runs through their U.S. partners or owners.

According to the Form 8802 instructions, you generally can't get Form 6166 if:

• You didn't file a U.S. return you were required to file.
• You filed as a nonresident, for example on Form 1040-NR or Form 1120-F.
• You're a dual-resident individual who has determined, or intends to determine, that you're not a U.S. resident under a treaty tie-breaker rule.
• Your entity is a U.S. partnership, grantor trust or disregarded LLC with no U.S. partners, beneficiaries or owners.
• Your exempt organization was organized outside the United States.
• Your employee benefit plan trust is in its first year, unless a qualified custodian bank administers it.

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How to get a U.S. Tax Residency Certificate: step by step

1. Ask the foreign office exactly what it needs. Confirm the country, the tax year or years, how many originals, and whether the certificate must be apostilled or legalized. Many offices keep the original.
2. Complete Form 8802. One application can cover several countries and tax years. On line 11, enter how many Forms 6166 you need for each country, so you get enough originals in one go. Sign and date the form: the IRS won't consider an unsigned application complete.
3. Add a penalties-of-perjury statement if you need one. Requests for the current tax year must include a statement, signed under penalties of perjury, that you are a U.S. resident and will remain one for the year. If your prior-year return isn't filed yet and isn't yet due, the statement must cover the prior year as well.
4. Pay the user fee. On Pay.gov, search "IRS Certs" and pay by bank account (ACH), debit card or credit card, then write the confirmation number on page 1 of Form 8802. Without it, the IRS won't process the form. You can also pay by check or money order.
5. Submit the application. Pay.gov asks you to upload a copy of Form 8802, but that copy is only used to validate the payment. You still have to mail or fax the complete application. Mail goes to the IRS in Philadelphia, at the address the instructions give for your payment method. If you paid on Pay.gov, you can fax it to 877-824-9110 (toll-free, U.S. only) or 304-707-9792 (inside or outside the U.S.), with up to 10 applications and 100 pages per fax and a cover sheet stating the page count. Individuals can file free through the IRS mobile-friendly Form 8802 instead. It isn't available for business entities.
6. Track it. The IRS will contact you after 30 days if processing will be delayed. You can call 267-941-1000 and choose the U.S. residency option, or check the IRS processing status page.
7. Apostille the original if the foreign office asks. Send the original Form 6166, as issued, to be authenticated by the U.S. Department of State. Don't staple, laminate, write on or notarize it.

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Special cases

• Partnerships and LLCs taxed as partnerships. A domestic partnership is not itself a U.S. resident for treaty purposes, even if all its partners are. The application lists each partner's name and TIN, with authorization from each partner, including partners in tiered partnerships. A fiscally transparent entity pays one $230 fee for all Forms 6166 issued under its EIN.
• Single-member LLCs and other disregarded entities. The entity isn't a U.S. resident on its own. The owner must be, and the owner's information goes on line 6. If the owner hasn't filed Form 8832, line 10 needs a penalties-of-perjury statement.
• Accountants, attorneys and other third parties. Form 2848 lets a recognized representative, such as an attorney, CPA or enrolled agent, act for you. Form 8821 only authorizes disclosure of tax information and can't authorize anyone to sign Form 8802. Write "See attached authorization" on line 3b.
• VAT exemptions. Form 6166 can serve as proof of U.S. residency for a foreign VAT exemption, but the IRS certifies only your federal income tax status, not the other conditions for the exemption.
• Indonesia. Form 6166 replaces Part III of Form DGT-1, or the last part of Form DGT-2. You still complete the rest of the Indonesian form.
• Treaty changes. The current Form 8802 instructions note the U.S.–Chile income tax treaty, in force since December 19, 2023; the termination of the 1979 U.S.–Hungary convention; and partial suspensions of the treaties with Russia and Belarus.

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Mistakes that delay a Form 6166 request

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After you receive it: apostille or embassy legalization

Many foreign tax offices, banks and courts want the original Form 6166 with an apostille. Because the certificate is a federal document, a state Secretary of State can't apostille it. Only the U.S. Department of State's Office of Authentications can.

• Hague Apostille Convention countries, such as Greece: the State Department attaches an apostille to the original certificate.
• Countries outside the Hague Convention, such as the UAE, Qatar, Kuwait and Egypt: the State Department issues an authentication certificate, and the country's embassy or consulate then legalizes it. See embassy legalization.
• Thailand still requires embassy legalization and moves to the apostille system on February 28, 2027. See Thailand legalization.

Our Washington, DC team reviews your original certificate, completes Form DS-4194, hand-delivers it to the State Department and ships the apostilled Form 6166 anywhere in the world. Expedited service takes 9 business days. See U.S. Tax Residency Certificate (Form 6166) apostille.

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Get your Form 6166 apostilled

Washington, DC office: 2001 L Street NW, Suite 545, Washington, DC 20036
Arlington, VA office: 5315 Langston Boulevard, Suite B, Arlington, VA 22207
Phone: 202-247-0837 | Email: support@dcmobilenotary.com

→ Form 6166 apostille service
→ Free 24-hour pre-check
→ Federal apostille for other U.S. documents

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Frequently asked questions

Is a U.S. Tax Residency Certificate the same as Form 6166?
Yes. The IRS issues U.S. residency certification on Form 6166. Foreign offices may call it a certificate of tax residence, a residency certificate or a tax residency letter.

How long does it take to get Form 6166?
The IRS asks you to apply at least 45 days before you need it and will contact you after 30 days if processing will be delayed. Getting it apostilled takes 9 business days with our expedited service.

How much does Form 8802 cost in 2026?
For applications postmarked on or after October 1, 2026, $105 for individuals and $230 for businesses and other entities. It's one fee per application, however many countries, years or copies you list.

Can I apply for Form 6166 online?
Individuals can file free through the IRS mobile-friendly Form 8802. Businesses and other entities mail or fax Form 8802, and anyone can pay the fee online through Pay.gov.

When can I request a certificate for the current year?
Your request can't be postmarked before December 1 of the prior year, and it must include a statement signed under penalties of perjury that you are a U.S. resident.

Can I get Form 6166 if I filed Form 1040-NR?
Generally no. If you filed as a nonresident, the IRS generally can't certify you as a U.S. resident for that year.

How many copies of Form 6166 can I get?
As many as you list on line 11 of Form 8802, for each country. The user fee stays the same because it's charged per application.

Can my LLC get Form 6166?
A single-member LLC is certified through its U.S.-resident owner. An LLC taxed as a partnership is certified for its U.S. partners, with each partner's details and authorization.

Does Form 6166 need an apostille?
Only if the receiving office asks for one. When it does, only the U.S. Department of State can apostille it, on the original certificate.

Can I use Form 6166 for a foreign tax credit?
No. Form 6166 certifies residency. It can't be used to prove that U.S. tax was paid.

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Official sources

• IRS — Form 6166, Certification of U.S. Tax Residency: https://www.irs.gov/individuals/international-taxpayers/form-6166-certification-of-us-tax-residency
• IRS — Instructions for Form 8802: https://www.irs.gov/instructions/i8802
• IRS — Form 8802 user fee fact sheet: https://www.irs.gov/individuals/international-taxpayers/form-8802-application-for-united-states-residency-certification-user-fee-fact-sheet
• IRS — Mobile-friendly Form 8802: https://www.irs.gov/dmaf/form/f8802
• IRS — Processing status for tax forms: https://www.irs.gov/help/processing-status-for-tax-forms
• U.S. Department of State — Request authentication services: https://travel.state.gov/en/replace-certify/authenticate-documents/request-services.html

This article is general information about tax residency certification and document authentication procedures, not legal or tax advice. Government fees, forms and requirements change. Confirm what your receiving authority requires before you submit.