Fax Form 8802: US Residency Certification
Need Form 6166 to claim tax treaty benefits abroad? Submit Form 8802 by fax after paying on Pay.gov. Here's the complete process.
10 pages free every month. No credit card.
What This Form Does
Form 8802 is your application for US tax residency certification. The IRS responds with Form 6166, an official letter on Treasury Department letterhead certifying you're a US tax resident. You need Form 6166 to claim income tax treaty benefits or VAT exemptions in foreign countries. Common uses: reducing withholding on foreign income, claiming treaty benefits on foreign investments, and VAT refunds in EU countries.
The Two-Step Process (Since Sept 2024)
- Step 1: Go to Pay.gov, search "IRS Certs," and pay the user fee ($105 for individuals, $230 for non-individuals). Upload your Form 8802 as a PDF. You'll receive an Agency Tracking ID — write this on page 1 of your form.
- Step 2: Fax the form to (877) 824-9110 (toll-free) or (304) 707-9792 (domestic/international). Maximum 10 forms per fax, 100 pages total.
The IRS will NOT process Form 8802 without the e-payment confirmation number. For accepted files, page limits, and what happens after you send, see how to send a fax.
What Comes Back: Form 6166
The IRS mails Form 6166 from Philadelphia after 6 to 10 weeks of processing. It cannot be faxed or emailed. For expedited delivery, you can include a prepaid DHL (international) or FedEx/UPS (domestic) label and envelope with your submission. Submit at least 45 days before you need the certification.
How to get Form 6166
Form 6166 is not a form you fill in. It is the letter the IRS issues, on Treasury letterhead, after it approves Form 8802. The application is Form 8802. Each Form 8802 can request certifications for more than one country and more than one tax year, and the foreign tax authority that wants proof of US residency is the one you give the Form 6166 to. If you already hold a Form 6166 and need a new one for another year, that is a new Form 8802.
How to Fax with FaxTerra
After completing the Pay.gov payment and writing the confirmation number on your form, save as PDF. Upload to FaxTerra, enter (877) 824-9110, and send. Include a cover sheet stating your page count. Free for up to 10 pages per month. Keep your delivery confirmation. The IRS does not acknowledge receipt, so it is your record of when the IRS line took your pages; the proof-of-filing guide covers what it does not show.
Non-US founders applying for treaty benefits typically also need an EIN first: see Form SS-4, EIN Application and the EIN for Non-US Residents guide. For other IRS forms you can fax, see How to Fax the IRS and the IRS Fax Numbers Directory.
See how to send a fax with FaxTerra
Frequently Asked Questions
What is the fax number for Form 8802?
Toll-free: (877) 824-9110. Non-toll-free (domestic or international): (304) 707-9792. Maximum 10 forms and 100 pages per fax transmission.
How much does Form 8802 cost?
$105 per application for individuals. $230 for non-individuals (corporations, partnerships, trusts). Paid on Pay.gov before faxing. The IRS will not process the form without payment.
How long until I receive Form 6166?
6 to 10 weeks by standard mail from IRS Philadelphia. During peak periods, allow 8-10 weeks. Include a prepaid courier label for faster delivery.
Can I receive Form 6166 by fax?
No. Form 6166 is delivered by mail only. It cannot be faxed, emailed, or downloaded. Submit Form 8802 at least 45 days before you need the certification.
Where are the Form 6166 instructions, and is there a Form 6166 application?
There is no Form 6166 to fill in. Form 6166 is the certification letter the IRS issues; Form 8802 is the application for it, and the Instructions for Form 8802 are the instructions that apply. Pay the user fee on Pay.gov, then fax or mail Form 8802 as described above.