Need to fax IRS forms but not sure which ones are accepted or what numbers to use? This complete 2026 guide covers every faxable IRS form, verified fax numbers by form and state, and a step-by-step process to fax from your phone in minutes.
Frequently Asked Questions
Can I fax any IRS form?
No — the IRS only accepts specific forms by fax. Forms commonly accepted include SS-4, 2553, 2848, 8821, 4506-T, and 3911. Original tax returns (Form 1040, 941, 1120) and most routine filings must be e-filed or mailed. Always verify the fax number on the form's official IRS instructions before sending.
What is the IRS fax number for Form SS-4 (EIN application)?
For applicants in the 50 states or D.C.: 855-641-6935. For applicants in U.S. territories or within the U.S. but outside the 50 states: 855-215-1627. For applicants outside the U.S.: 304-707-9471. The IRS returns your EIN by fax within 4 business days, so include your fax number on the form.
How do I confirm the IRS received my fax?
The IRS does not send a fax confirmation receipt. Your transmission log — showing the IRS fax number, date, time, and pages sent — is your proof. Save it immediately. Services like mFax provide automatic delivery confirmation by email. You can also call 1-800-829-1040 to ask the IRS to verify receipt.
Do I need a fax cover sheet when faxing IRS forms?
It is strongly recommended. An IRS fax cover sheet should include your name, taxpayer ID or EIN, the form number being sent, the total page count, your fax number for callbacks, and a confidentiality notice. See our [IRS fax cover sheet guide](/blog/irs-fax-cover-sheet/) for a free template.
Can I fax IRS forms from my phone?
Yes. Apps like mFax let you scan or upload your completed IRS form, enter the IRS fax number, and send — all from your iPhone or Android in under 2 minutes. You receive a digital delivery confirmation automatically, which serves as your transmission proof.