Fax Form SS-4 to the IRS and Get Your EIN
The online EIN tool not working? Can't use it from outside the US? Fax your SS-4 free, no fax machine needed. The IRS targets 4 business days; across real fax-backs to FaxTerra numbers, about 2 weeks is typical.
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When does the IRS fax your EIN back?
The IRS faxes your EIN back to the number on your SS-4, usually within a couple of weeks and occasionally longer than a month. That fax-back is the EIN assignment notice, not the CP 575 confirmation letter, which the IRS mails separately. Measured from real EIN fax-backs to FaxTerra users (n=159).
See full IRS response-time dataIRS Fax Numbers for Form SS-4
- Domestic (50 states + DC): (855) 641-6935
- International from within the US: (855) 215-1627
- International from outside the US: (304) 707-9471
The Fax-TIN service operates 24/7, 365 days a year. Form SS-4 has a field for your return fax number in the signature block, labeled "Applicant's fax number." Fill it in, and put the same number on your cover sheet, so the IRS can fax your EIN back to you.
Who Needs to Fax SS-4?
The IRS online EIN tool works for most US applicants — but not everyone. You'll need to fax if: you're a non-US resident without an SSN or ITIN, you hit a Reference Number error (101, 105, 106, 107, or 115) on the online tool, or you need to include supporting documents like Articles of Organization. International founders forming US LLCs through Stripe Atlas, Amazon, or Shopify commonly use the fax path.
What the IRS Sends Back
After receiving your faxed SS-4, the IRS faxes back a notice carrying your assigned EIN. The IRS targets 4 business days for this; plan for longer. Measured across real fax-backs to FaxTerra numbers, about 2 weeks is typical and 87% arrive within three weeks; a minority run past a month. The full distribution is published on our measured IRS response-time data page.
That fax-back is NOT the CP 575 confirmation letter, which arrives separately, by mail. Keep both: the fax-back for immediate use (opening bank accounts, starting payroll) and the CP 575 for permanent records. If the CP 575 never arrives, you can request a Letter 147C replacement by phone.
How to Fax Form SS-4 with FaxTerra
Download Form SS-4 from IRS.gov, fill it out completely, and save as a PDF. Upload it here, enter (855) 641-6935 (or the international number), and send. FaxTerra transmits at high resolution automatically, so your form goes through clear and legible — there are no settings to adjust. Before you send, put your FaxTerra number in the "Applicant's fax number" field in the form's signature block, and add it to a cover sheet as well. That is how the IRS knows where to fax your EIN back. Your delivery confirmation is your proof of filing.
Tips for Success
Fill out every field: incomplete forms are rejected without notice. One field is easy to miss: "Applicant's fax number" in the signature block. Without it the IRS has nowhere to fax your EIN back, and you are left calling to chase it. Double-check the Responsible Party's SSN or ITIN (Line 7b). If the responsible party doesn't have and can't get an SSN or ITIN, enter "foreign" or N/A in the field, per the IRS instructions. Start from a sharp, legible scan or photo: FaxTerra transmits at high resolution automatically, so a clean source document is all you need. The Fax-TIN service runs 24/7, so if the line is busy, just retry. Non-US founders should also read the EIN for Non-US Residents guide for international-specific timelines and the phone-followup playbook. Once you have your EIN, you may also need to request a 147C verification letter: banks require official IRS proof of your EIN before they will open a business account. For the broader picture of what the IRS accepts by fax, see How to Fax the IRS. When you send from a FaxTerra number, your inbox catches the reply and labels a fax from a known IRS line, and the composer can add a check-in: if nothing has arrived after three weeks, one email tells you it is time to call instead, with the script. We do not fill in your form, choose your entity type, advise you, or contact the IRS on your behalf. See faxing the IRS about an EIN for what the wait actually looks like and what to do when the reply does not come.
Frequently Asked Questions
What is the IRS fax number for Form SS-4?
Domestic: (855) 641-6935 (toll-free). International from within US: (855) 215-1627. International from outside US: (304) 707-9471. All numbers accept faxes 24/7.
How long does it take to get an EIN after faxing?
The IRS targets 4 business days. In practice it takes longer: measured across real fax-backs to FaxTerra numbers, about 2 weeks is typical and 87% arrive within three weeks; a minority run past a month. You must include a return fax number on your SS-4 and cover sheet. The formal CP 575 confirmation letter arrives separately, by mail.
Can I fax Form SS-4 for free?
Yes. FaxTerra offers 10 free pages per month. Form SS-4 is 1 page (2 with a cover sheet), well within the free limit. See free faxing for exactly what every account includes each month.
Can I apply for an EIN online instead?
Yes — if you have an SSN or ITIN and your principal business is in the US. The online tool at irs.gov assigns an EIN instantly. If you can't use the online tool (non-US resident, reference number errors), fax is the fastest alternative.
What is a Reference Number 101 error?
Reference 101 means the IRS found a business name too similar to an existing entity. You'll need to fax Form SS-4 with your filed Articles of Organization/Incorporation for manual review. The online tool cannot resolve this.
Do I need a fax number to receive the EIN back?
Yes. Include a return fax number on your SS-4 cover sheet. If you don't have a fax number, FaxTerra's Starter plan ($4.99/month) gives you a dedicated US fax number that receives the IRS reply directly to your email.
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