How to Fax the IRS: Fax Numbers & Step-by-Step Guide

What you can fax are specific supporting documents and forms — either when requested by an IRS agent during an audit, or when a notice asks for additional information. The most commonly faxed forms include:

• Form SS-4 — EIN application
• Form 2553 — S-corporation election
• Form 8821 / Form 2848 — Tax information authorization / Power of attorney
• Forms 8886, 8918, 8806, 8023 — Business and transaction disclosures
• Supporting documents requested via CP notices (e.g., CP75, CP518) — your notice will specify the fax number to use

Use this reference table to find the correct number for your form. These numbers are current as of 2026 — always cross-check against your notice or the official form instructions on IRS.gov, as they can change.

1. 1
   Verify your form is fax-eligible and find the correct number

   Use the table above or check the specific notice or form instructions you received. If you're responding to a CP notice, the correct fax number is printed directly on it — always use that number over any list.

2. 2
   Prepare your documents

   Complete all required fields — the IRS will reject incomplete forms. If you filled out forms by hand, ensure your handwriting is clear and dark. Scanned documents should be at least 200 DPI resolution. Blurry or low-quality faxes may be rejected.

3. 3
   Create a cover sheet

   Include: your full name, SSN or EIN, tax year in question, notice number (if responding to a letter), phone number, total number of pages, and a brief description of what you're sending. The IRS processes thousands of faxes daily — a clear cover sheet prevents your documents from getting lost. Also include your return fax number if you expect a response (required for SS-4 EIN applications).

4. 4
   Mark your name and SSN/EIN on every page

   Pages can get separated during IRS processing. Having your identifying information on each page ensures your documents stay matched to your case even if the cover sheet is separated.

5. 5
   Choose your faxing method and send

   If using QuickFax: upload your documents (PDF, Word doc, or photo), enter the IRS fax number, and pay $1.50/page. No account needed. If using a physical machine or another service, follow their process — see the comparison section below for options.

6. 6
   Confirm delivery and save your proof

   QuickFax shows live transmission status and emails you a timestamped delivery confirmation. Save this email — it is your proof of timely submission if the IRS ever claims they didn't receive your documents. For physical fax machines, keep the printed confirmation page.

Most people no longer own fax machines, yet the IRS still requires faxing for many submissions. You have three real options:

For IRS faxing specifically, QuickFax's mobile optimization matters — if you're racing a deadline and only have your phone, you can photograph your IRS documents and fax them immediately from wherever you are. Works in Safari and Chrome with no download required.

Transmission itself is fast — 1–3 minutes per page. But IRS processing time (when they actually review and act on your documents) is a separate matter entirely.

Your QuickFax delivery confirmation proves timely submission even if the IRS takes weeks to process. As long as you faxed before the deadline, you've met your obligation — the processing timeline is the IRS's responsibility, not yours.

If you haven't heard back within the expected timeframe, call the number on your notice with your delivery confirmation in hand to verify they received your fax.

Before faxing, it's worth checking whether any of these alternatives apply to your situation:

• IRS Document Upload Tool: Available for certain notices that include a unique access code. When applicable, it's free and faster than faxing. But it only works for specific notice types — if your notice doesn't include an access code, you'll need to fax or mail.
• IRS e-file: Required for complete Form 1040 returns. Use tax software or a tax professional — you cannot fax or upload your full return.
• IRS online EIN application: If you're applying for an EIN (Form SS-4) and your business qualifies, the online application at IRS.gov is instant. Only fax if you don't qualify for online application (international entities, trusts, estates).
• Certified mail: A reliable alternative to faxing, but adds 7–10 days for delivery and requires a post office visit. Useful if IRS fax lines are consistently busy near your deadline.

For time-sensitive IRS requests where you've received a notice with a deadline, faxing tax documents online is faster than mail and provides same-day delivery confirmation.

For a typical 2–4 page IRS submission, QuickFax costs $3–$6 total — versus $15–$25 for a subscription service's first month (which you then need to remember to cancel) or 30–60 minutes of your time driving to a retail location.