IRS EIN Reference Number 101: What It Means and How to Fax Form SS-4
We fill Form SS-4, fax it to the IRS and give you a 90-day return fax number.
If the IRS online EIN application stopped with reference number 101, you can still get an EIN. The usual route is to call the IRS or to send Form SS-4 by fax so a person reviews it.
What the reference number 101 message says
The online assistant shows a message like this (wording from an IRS procedure alert published on IRS.gov):
We are unable to provide you with an EIN. We apologize for the inconvenience, but based on the information provided we are unable to provide you with an EIN through this online assistant. Please call 800-829-4933 for assistance. When outside the US, call 267-941-1099. TTY/TDD: 800-829-4059. Please have your information readily available and mention reference number XXX.
The same IRS document says calls about reference numbers 101 or 115 are directed to a customer service representative, while other reference numbers get an automated message about correcting invalid information.
What usually causes it
The IRS does not publish a public list of what each reference number means. Applicants and formation services most often report that 101 appears when the business name matches, or is very close to, an entity the IRS already has. That is a commonly reported cause, not an official IRS definition, so treat it as a likely explanation rather than a certainty.
Your two options
- Call the IRS at 800-829-4933 (267-941-1099 from outside the US) and mention reference number 101. An assistor can review the application.
- Fax Form SS-4 so the IRS processes it manually. Many applicants include a copy of the filed formation document (for example articles of organization) when the name is the likely issue.
Where to fax Form SS-4
| Your situation | IRS fax number |
|---|---|
| Principal business, office or agency, or legal residence, in one of the 50 states or DC | 855-641-6935 (Fax to this number now) |
| No such location in any state; faxing from within the US | 855-215-1627 (Fax to this number now) |
| No such location in any state; faxing from outside the US | 304-707-9471 (Fax to this number now) |
Source: IRS where to file Form SS-4, checked 14 October 2026.
How to fax the SS-4 after a 101 error
- Fill in Form SS-4 with the same legal name and responsible party you used online. Check the spelling against your state formation document.
- Sign it. Unsigned applications are not processed.
- Put a working return fax number on the form so the IRS can fax the EIN back. A 24-hour number is usually too short; a 30-day number gives you time.
- Fax it to the number in the table above and keep the transmission receipt.
The IRS processing-status page (reviewed 2 October 2026) lists faxed Form SS-4 as processed 10 business days after receipt.
Prefer not to do it yourself? Get an EIN by fax for $19.99: we fill Form SS-4 from your answers, fax it to the right IRS number and give you a return fax number for the reply. For more detail on every SS-4 line, read the Form SS-4 walkthrough.