If you operate a business, work as a tax professional, or need to manage personal tax matters, you may need to submit certain tax forms or notice responses to the IRS. While digital options exist, the Internal Revenue Service (IRS) still accepts fax for some critical forms and correspondence.
For many startups, foreign entrepreneurs, and individuals, sending a physical fax is difficult. Modern laptops and smartphones don't have phone jacks, and local print shops can be unreliable.
This guide will explain:
- Which IRS tax forms are commonly submitted by fax.
- Where to verify the current IRS fax number for each form.
- How to prepare your PDF documents and cover sheets.
- How to fax tax forms to the IRS online securely from your browser.
- What proof of delivery you should keep for your records.
1. Which IRS forms can you submit by fax?
The IRS does not accept faxes for every type of filing. Standard annual income tax returns (like Form 1040, 1120, or 1065) generally must be filed electronically (e-filed) or mailed. However, the IRS accepts faxes for specific applications, authorizations, and notice responses:
Form SS-4 (Application for Employer Identification Number)
If you are a non-US resident or an international business without a Social Security Number (SSN) or Individual Taxpayer Identification Number (ITIN), you cannot apply for an EIN online. The official way is to fax Form SS-4.
- IRS Fax Number (International Applicants): +1 (304) 707-9471
- IRS Fax Number (US Applicants): +1 (855) 641-6935
Form 8821 (Tax Information Authorization)
Form 8821 authorizes an appointee to receive and inspect your confidential tax information. The IRS accepts Form 8821 by fax to CAF units, but the correct fax number depends on the current IRS instructions and the taxpayer's location.
Form 2848 (Power of Attorney and Declaration of Representative)
Form 2848 is used to authorize an individual (like a CPA or tax attorney) to represent you before the IRS. Like Form 8821, it should be sent to the CAF fax number listed in the latest IRS instructions for your situation.
Form 2553 (Election by a Small Business Corporation)
Used by domestic corporations or LLCs to elect S-Corporation tax status.
Responses to IRS Notices (e.g., CP2000, CP504, CP12)
If you receive an official letter or notice from the IRS requesting additional information, the notice will almost always include a dedicated fax number to submit your response and supporting documentation.
2. How to verify the correct IRS fax number
Always check the latest instructions on IRS.gov before sending, as IRS fax numbers can change and some forms route by taxpayer location or notice type.
Useful official references:
- Form SS-4 instructions for EIN applications.
- Form 2848 instructions for power of attorney submissions.
- Form 8821 instructions for tax information authorization submissions.
Do not reuse a fax number from one IRS form for another form. For example, the SS-4 Fax-TIN numbers are not the same as the CAF numbers for Forms 2848 and 8821.
3. Preparing Your PDF and Cover Sheet
When submitting documents to the IRS via fax, follow these strict rules to avoid rejection:
- Always Include a Fax Cover Sheet: The cover sheet must state the Taxpayer Name, Taxpayer Identification Number (TIN/SSN/EIN), the specific Form Number being submitted, the number of pages, and the sender's contact details.
- High Contrast and Resolution: IRS agents scan received faxes into their database. Handwritten signatures and text must be in dark ink, clear, and high contrast.
- Correct Format: Save all pages, including the cover sheet, into a single PDF document. The file size should be under 10MB.
- Signatures: Follow the signature rules in the current IRS form instructions. If you are unsure whether an electronic signature is accepted for your form, print the page, sign it with a pen, and scan it back to PDF.
4. How to Fax Your Tax Forms Online in 4 Steps
You can send your tax forms to the IRS securely using our browser-based online fax tool. No account signup or software installation is required.
Step 1: Upload Your PDF Tax Form
Go to Send Fax Online, drag and drop your prepared PDF (including the signed form and cover sheet) into the upload area.
Step 2: Select Country & Enter IRS Fax Number
Select United States (+1) from the country dropdown. Enter the target IRS fax number.
For example, if you are faxing an international SS-4 application to +1 (304) 707-9471, enter 3047079471.
Step 3: Enter Your Email for Status Updates
Select Guest Checkout (or sign in using your account). Input your email address to receive immediate delivery status receipts.
Step 4: Pay and Transmit
Select your payment method (PayPal or Credit Card) and finalize the checkout. Once paid, the system encrypts your PDF, queues it directly to our fax gateway, and initiates transmission to the IRS.
5. Keep Proof of Transmission
For tax compliance, keep a delivery confirmation showing that you submitted your documents on time.
Once your fax is successfully received by the IRS machine, we will send a Delivery Receipt to your email. This receipt includes:
- The transmission status (Delivered).
- The exact timestamp of delivery.
- The recipient IRS fax number.
- The number of pages sent.
Save this email or print it out. If you later need to show when and where you sent the form, the receipt gives you a supporting transmission record.
Ready to send your tax forms? Go to Send Fax Online to transmit your documents securely now.