Fax IRS Forms: Complete Guide (2026)

By David Thompson · Published March 15, 2026 · Updated April 10, 2026 · 9 min read

Faxing IRS forms is one of the fastest ways to submit time-sensitive tax documents with an instant timestamp and a traceable delivery record. But the IRS doesn't accept every form by fax — and using the wrong fax number sends your documents to the wrong processing center, causing delays or rejection.

This guide covers every faxable IRS form, the verified 2026 fax numbers for each one, and a step-by-step process so your submission reaches the right desk the first time.

Which IRS Forms Can Be Faxed?

Not all IRS forms are fax-eligible. The IRS explicitly designates which forms may be submitted by fax and publishes specific fax numbers for each. Sending a non-faxable form will result in it being ignored or returned.

Forms the IRS Accepts by Fax

The following forms have official IRS fax numbers and can be submitted by fax:

Forms That Cannot Be Faxed

The IRS does not accept these forms by fax — they must be e-filed or mailed:

• Form 1040 — Original individual income tax returns (see our Form 1040 fax guide for when exceptions apply)
• Form 941 — Quarterly payroll tax returns
• Form 1120 — Corporate income tax returns
• Form 4868 — Application for automatic tax extension
• Form 8822 — Change of address
• Form 8962 — Premium tax credit
• Form 8850 — Work Opportunity Tax Credit pre-screening

IRS Fax Numbers by Form (2026 Reference)

Form SS-4 — EIN Application

Form SS-4 lets you apply for an Employer Identification Number by fax. The IRS will fax your EIN back to you within 4 business days. The Fax-TIN program is available 24/7.

Important: Include your fax number on the form — the IRS needs it to return your EIN.

Source: IRS Instructions for Form SS-4 (December 2025)

For a deeper walkthrough, see our complete guide to faxing the IRS.

Form 2553 — S Corporation Election

Faxing is the preferred method for Form 2553 — it provides a date-stamped transmission record proving you met the filing deadline, which matters if the IRS ever questions your election timing.

The fax number depends on the state where your corporation's principal business office is located.

Eastern states (CT, DE, DC, GA, IL, IN, KY, ME, MD, MA, MI, NH, NJ, NY, NC, OH, PA, RI, SC, TN, VT, VA, WV, WI):

Fax: 855-887-7734

Western states (AL, AK, AZ, AR, CA, CO, FL, HI, ID, IA, KS, LA, MN, MS, MO, MT, NE, NV, NM, ND, OK, OR, SD, TX, UT, WA, WY):

Fax: 855-214-7520

Source: IRS Where to File — Form 2553

For full deadline rules and a step-by-step faxing guide, see our Form 2553 fax guide.

Form 2848 — Power of Attorney

Form 2848 authorizes a tax professional or representative to act on your behalf with the IRS. The IRS also accepts Form 2848 through its secure online submission portal, which is faster than fax for most filers.

Processing time: 3–5 business days after the CAF unit receives the form.

Form 8821 — Tax Information Authorization

Form 8821 lets a designated third party receive your tax information from the IRS — without granting them the right to act on your behalf. The fax numbers are the same as Form 2848:

Form 4506-T — Request for Transcript of Tax Return

Form 4506-T lets individuals and businesses request tax return transcripts. The correct fax number is determined by your state of residence (for individuals) or your principal business location (for businesses).

Individual Transcripts (Form 1040, W-2, 1099):

Source: IRS Where to File Addresses — Form 4506-T

Form 3911 — Taxpayer Statement Regarding Refund

Use Form 3911 to trace a missing or lost refund check. Do not send anything other than Form 3911 to these fax numbers.

Source: IRS About Form 3911

Other Faxable Forms

How to Fax IRS Forms in 5 Steps

Tips for Successful IRS Fax Submissions

• ✓Use the current version of each form — check the revision date in the form's lower left corner and verify against IRS.gov
• ✓Type or use a PDF form-fill tool rather than handwriting — IRS processing centers use OCR scanning
• ✓Send only one form type per fax — don't combine Form 2848 and SS-4 in a single transmission
• ✓Include a cover sheet on every submission — it routes your documents and provides a contact number for IRS follow-up
• ✓Fax during business hours (8 a.m.–4 p.m. local IRS time) when possible — reduces queue time
• ✓Save your fax confirmation immediately — the IRS will not resend receipts and cannot verify receipt without your transmission log
• ✓Use a toll-free fax service — most IRS fax numbers are toll-free (855/844/877 prefixes), but some international numbers are not
• ✓Keep a copy of everything you send — the IRS may request it again months later

Fax vs. Mail vs. Online for IRS Submissions

Use fax when:

• You're filing close to a deadline (fax timestamp = proof of timely filing)
• You're responding to an IRS notice that gives a specific fax number
• You need your EIN quickly (SS-4 by fax: 4 business days)
• The IRS explicitly instructed you to fax during a phone call

Use mail when:

• The form is not fax-eligible
• You're sending original documents that must be physically received
• Your submission includes items that don't fax well (photos, certified copies)

Send Your IRS Fax Now

You don't need a fax machine to fax IRS forms. mFax lets you upload your completed form, enter the IRS fax number from this guide, and send — from your phone or computer in under 2 minutes. You'll receive a timestamped delivery confirmation automatically.

Over 5 million people use mFax for exactly this kind of time-sensitive document submission. No hardware, no store trip, and the confirmation doubles as your filing proof.

Send your IRS fax at mFax.to →

Related Guides

• How to Fax to the IRS: Complete 2026 Guide — General overview of faxing any document to the IRS
• How to Fax Form 1040 to the IRS — When 1040-related documents can and cannot be faxed
• How to Fax Form 2553 (S Corp Election) — Step-by-step guide with deadline rules
• Fax Form 4506-C to the IRS — Guide for IVES participants and lenders
• IRS Fax Cover Sheet: Free Template — Required cover sheet with downloadable template