By David Thompson · Published May 5, 2026 · Updated June 8, 2026 · 7 min read
Quick Answer: The IRS accepts faxes for specific business forms — SS-4, 2553, 2848, 8655, and more — but not for most tax returns. Send them in minutes from any phone or browser with mFax.to.
Running a business means dealing with IRS paperwork that can't always wait for the mail. Whether you're applying for an EIN, electing S-Corp status, or authorizing a tax representative, faxing business IRS tax forms is often the fastest option — cutting days off the process compared to mailing.
The IRS is specific about which forms can be faxed, which fax number to use, and how to send them securely. This guide covers every major business form the IRS accepts by fax, the verified fax numbers for 2026, and a step-by-step process to send them right the first time.
Always Verify Before Sending
IRS fax numbers change. Before sending, confirm the correct number on the official form instructions at IRS.gov — not from memory or a third-party source.
Which Business IRS Tax Forms Can You Fax?
Not all IRS forms accept fax submissions. The IRS only allows faxing for specific forms — most business tax returns must be e-filed or mailed.
| Form | Purpose | Faxable? |
|---|---|---|
| SS-4 | Apply for EIN (Employer Identification Number) | ✅ Yes |
| 2553 | Elect S-Corporation tax status | ✅ Yes |
| 2848 | Power of Attorney (authorize a representative) | ✅ Yes |
| 8821 | Tax Information Authorization | ✅ Yes |
| 8655 | Reporting Agent Authorization | ✅ Yes |
| 3115 | Application for Change in Accounting Method | ✅ Yes |
| 4506-T | Request for Tax Transcript (IVES participants) | ✅ Yes |
| 8806 | Certain corporate elections | ✅ Fax only |
| 941 | Employer's Quarterly Federal Tax Return | ❌ E-file or mail |
| 1120 | U.S. Corporation Income Tax Return | ❌ E-file or mail |
| 1120-S | S-Corp Income Tax Return | ❌ E-file or mail |
| 8822-B | Change of Address or Responsible Party | ❌ Mail only |
Don't Fax Your Business Tax Return
Forms 941, 1120, and 1120-S cannot be faxed. These must be e-filed or mailed. Sending them by fax will result in the submission not being processed.
IRS Fax Numbers for Business Tax Forms (2026)
Use only the fax numbers published in the official IRS form instructions. The numbers below are current as of 2026 — always cross-reference at IRS.gov before sending.
Form SS-4 — EIN Application
The Fax-TIN program lets you fax Form SS-4 and receive your EIN back by fax within 4 business days. You must include your own fax number on the form for the IRS to return your EIN.
| Location | IRS Fax Number |
|---|---|
| 50 U.S. states and D.C. | 855-641-6935 |
| U.S. territories (within U.S.) | 855-215-1627 |
| Outside the United States | 304-707-9471 |
For a detailed walkthrough, see our guide to faxing Form SS-4 to the IRS.
Form 2553 — S-Corporation Election
The fax number for Form 2553 depends on your business location. Check the current form instructions on IRS.gov for your state's assignment.
| Region | IRS Fax Number |
|---|---|
| Western and southern states (Ogden, UT) | 855-214-7520 |
| Northeastern and midwestern states (Kansas City, MO) | 855-887-7734 |
See our detailed Form 2553 fax guide for state-by-state assignments and deadline requirements.
Form 2848 — Power of Attorney
Form 2848 can be faxed to the IRS Centralized Authorization File (CAF) unit. The fax number varies by state — check the form's instructions or see our IRS Power of Attorney fax number guide.
Signature requirement: Form 2848 requires a wet ink (handwritten) signature. Digital signatures are not accepted for faxed submissions.
Form 8655 — Reporting Agent Authorization
| Fax Number | Transmission Limit |
|---|---|
| 855-214-7523 | Max 25 forms per transmission |
If you need to send more than 25 Forms 8655, split them into separate transmissions. The IRS recommends computer-based faxing (rather than a traditional fax machine) for this form.
Form 3115 — Change in Accounting Method
| Purpose | Fax Number |
|---|---|
| Automatic consent requests | 1-844-249-8134 |
Advance consent requests have different requirements — check the current Form 3115 instructions for details.
Form 4506-T — Tax Transcript Request
Form 4506-T faxing is available for IVES participants (Income Verification Express Service) only — typically lenders and financial institutions. Processing is approximately 2–3 business days.
Full IRS Fax Number Reference
A complete list of IRS fax numbers organized by form is available in our IRS fax numbers for different forms guide.
How to Fax Business IRS Tax Forms: Step by Step
Verify the Form is Faxable
Confirm on the official IRS form instructions at IRS.gov that your specific form accepts fax submissions. Do not rely on unofficial sources — the IRS does not accept all forms by fax, and using the wrong submission method delays your filing.
Complete the Form Carefully
Fill out every required field. For Forms 2848 and 8821, use a handwritten (wet ink) signature — electronic signatures are not accepted for faxed submissions. Print clearly and ensure all text is legible at 300 DPI or better.
Prepare Your IRS Cover Sheet
Create a cover sheet that includes:
- Your full name and phone number
- Your fax number (the IRS uses this to fax back confirmations or your EIN)
- Date of transmission
- Total page count including the cover sheet
- Form number and tax year
- Last 4 digits only of your SSN or EIN — never your full number on the cover sheet
See our IRS fax cover sheet template for a ready-to-use format.
Confirm the Correct IRS Fax Number
Look up the fax number in the official instructions for your specific form on IRS.gov. For state-dependent forms like SS-4 and 2553, verify you're using the number for your business location. Numbers change — verify for the current tax year.
Send via mFax.to
Open mFax.to on your phone or browser. Upload your completed form as a PDF, enter the IRS fax number, and send. You'll receive a timestamped delivery confirmation — this is your proof of submission.
Save Your Transmission Confirmation
The IRS does not send fax receipt confirmations. Your fax service's transmission report is the only documentation that your form was delivered. Save it with your tax records for at least 3–7 years. For Form SS-4, watch for the IRS to fax your EIN back within 4 business days.
Protecting Sensitive Business Tax Information
Business tax forms contain some of the most sensitive data your company handles — EINs, financial figures, responsible party details. Follow these practices every time you fax IRS forms.
On the cover sheet:
- Include only the last 4 digits of your SSN or EIN
- Mark the document "CONFIDENTIAL — TAX DOCUMENT"
- Never include banking or account numbers
When choosing a fax service:
- Use a digital fax service rather than a shared office fax machine — digital services encrypt transmission and provide delivery receipts with timestamps
- Avoid fax machines in libraries, copy centers, or hotels where outgoing faxes are stored in shared memory
Before hitting send:
- Triple-check the fax number against the official IRS form instructions — a dialing error sends your business tax information to an unknown recipient with no recall option
Shared Fax Machines Are a Security Risk
Shared office or retail fax machines often store recent transmissions in memory, and incoming documents sit in open trays. Use a private digital fax service for sensitive IRS correspondence. mFax.to delivers a timestamped confirmation receipt for every fax, giving you a documented audit trail.
IRS Processing Times for Faxed Business Forms
Faxing saves 2–3 days of mail transit time. The IRS processing clock starts when it receives the fax — not faster than a mailed form, but you skip the delivery delay.
| Form | Typical Processing Time |
|---|---|
| Form SS-4 (EIN) — Fax-TIN program | 4 business days (EIN faxed back) |
| Form 2553 (S-Corp Election) | 3–5 business days |
| Form 2848 (Power of Attorney) | 3–5 business days |
| Form 8821 (Tax Information Authorization) | 3–5 business days |
| Form 4506-T (Transcript — IVES only) | 2–3 business days |
| Form 3115 (Accounting Method) | Varies by request type |
During peak tax season (January–April), processing takes longer. Build in extra time for filings near critical deadlines.
S-Corp Election Deadline
Form 2553 must be filed within 2 months and 15 days of your business's start date for the election to apply in the current tax year. Faxing is the fastest submission method and gives you a same-day timestamped confirmation.
Forms You Cannot Fax — What to Use Instead
The IRS requires these common business forms to be e-filed or mailed:
- Form 941 (Employer's Quarterly Federal Tax Return) — e-file or mail only
- Form 940 (Federal Unemployment Tax) — e-file or mail only
- Form 1120 / 1120-S (Corporate and S-Corp income tax returns) — e-file or mail only
- Form 8822-B (Change of Address or Responsible Party) — mail only, no fax accepted
- W-2 and 1099 filings — e-file via the IRS FIRE system
For a full breakdown of submission methods by form, see our complete IRS fax guide.
Send Business IRS Tax Forms Today
Faxing business IRS tax forms is still one of the fastest ways to submit critical filings — EIN applications, S-Corp elections, and power of attorney authorizations all move faster by fax than by mail.
mFax.to lets you send from any phone or browser in under 2 minutes. Upload your PDF, enter the IRS fax number, and get a timestamped confirmation as proof of submission — no fax machine, no office, no waiting.
For businesses with ongoing IRS correspondence, mFax Business gives your team a dedicated fax number, a shared inbox, and a full audit log of every submission — starting at about $9/mo (billed annually). Rather than locking you into fixed tiers, mFax lets you build your own plan: use the live calculator to dial in the exact seats and monthly pages your team needs and pay only for what you use.