Quick answer: Reference number 101 means the IRS online assistant found a business name too similar to an entity already in its records — and because the IRS checks all 50 states, a name your state approved can still conflict. You can’t clear it online. Fax Form SS-4 with your formation documents for manual review to 855-641-6935 (or 304-707-9471 from outside the US); the EIN usually comes back by fax in about four business days. Do not keep retrying online — once you hit 101, that entity is done with the online tool.
You filled in the IRS online EIN application, hit submit, and instead of a number you got a wall of apology and “reference number 101.” It is the most common EIN error there is, and the wording is vaguer than it needs to be — the assistant tells you it can’t issue an EIN but not why. Here is what actually triggered it, and the one reliable way to get your EIN anyway.
What Reference 101 actually means
In almost every case, 101 is a name conflict. The IRS system has flagged your entity’s name as identical or too close to a business already on file. The catch that trips everyone up: your Secretary of State only checks names within your own state, but the IRS database spans all 50 states and decades of entities. A name that is perfectly unique locally can still collide with a near-duplicate three states away. It does not mean your name is illegal or your business ineligible — only that the automated check can’t resolve the match on its own.
Less often, 101 is thrown by a mismatch on the responsible party — the individual whose name and SSN or ITIN you entered doesn’t line up with IRS records. That is worth ruling out first, because it has a faster fix than a true name conflict.
First, rule out a simple typo
Before you conclude it’s a genuine name conflict, check two things:
- The responsible party’s details. Their name must match their Social Security card exactly — not a driver’s licence, not a business card — and the SSN or ITIN must be entered correctly.
- Whether you already have an EIN. Sometimes the block means the entity was already assigned one. If so, you don’t need a new number — you need a copy, which the IRS provides as a 147C letter (our SS-4 guide covers that route).
What you should not do is resubmit the online form over and over with small name tweaks. Once an entity draws a 101, the online assistant is closed to it, and repeated attempts from the same details can trigger extra fraud scrutiny. One clean paper application is the way through.
The fix: fax Form SS-4 for manual review
Filing on paper routes your application to an IRS employee who reviews it by hand, which sidesteps whatever automated check is blocking you. You do not have to change your business name to do it. The steps:
- Download the current Form SS-4 (Rev. December 2025) from IRS.gov and complete it — entity name, responsible party and SSN/ITIN, entity type, and reason for applying.
- Attach your state formation documents — Articles of Organization, Certificate of Formation, or Articles of Incorporation. This isn’t strictly required by the form, but it lets the reviewer confirm your entity is legitimate and consistently speeds the manual review when a name conflict is the cause.
- Fax it to 855-641-6935 if the entity is in the 50 states or DC, or 304-707-9471 from outside the US. Use one method only — faxing and mailing the same application can land you two EINs.
- Wait about four business days for the EIN to come back by return fax, provided you gave a return fax number.
Four business days is the typical fax turnaround, but a manual review tied to a name conflict can run longer during IRS backlogs — some applicants report several weeks. If a deadline is looming (a bank account, a closing, payroll), fax as early as you can and keep your confirmation.
No fax machine? You don’t need one. Municorn Fax sends your completed SS-4 and formation documents to the IRS from your phone or computer, and gives you a timestamped delivery confirmation — useful proof of the date you filed if you later have to chase the application.
Should you call the IRS first?
It can be worth a call before you fax. Ring the Business & Specialty Tax Line at 800-829-4933; 101 cases are routed to a live representative rather than an automated menu, and that person can often see what your screen can’t — such as exactly which existing record the system is matching you to. Sometimes they can clear it so you finish online. Have the responsible party’s full legal name, SSN, and date of birth ready, plus the entity’s legal name and state of formation.
One thing the call will not do: hand you an EIN over the phone. The IRS no longer issues EINs by phone to domestic applicants, so if the conflict is real, the representative will point you to exactly the fax-or-mail route above. The call diagnoses; the fax resolves.
Every EIN reference number, decoded
101 is the common one, but the online assistant throws several codes. Here is what each means and the move.
| Reference | What it means | What to do |
|---|---|---|
| 101 | Business name too similar to an existing entity (checked across all states) | Fax or mail Form SS-4 with your formation documents for manual review |
| 102 | Responsible party’s SSN or ITIN doesn’t match IRS records | Recheck the number and name and reapply; if it persists, file SS-4 |
| 103 | An existing EIN entered as the responsible party doesn’t match | Verify the exact name and EIN from the CP 575 letter; call the IRS to confirm |
| 104 | A third-party designee’s address or phone matches the entity’s | Give the designee their own separate contact details and reapply |
| 105 | Too many online attempts with the same SSN, ITIN, or EIN | Wait 24 hours and reapply; if it persists, file SS-4 |
| 106 / 107 | Single-member LLC with no EIN on file (106) or too many already (107) | Call the IRS — these need a person to untangle |
| 109–113 | Temporary technical errors in the online assistant | Wait 24 hours and try again; or file SS-4 if it keeps failing |
| 114 | The responsible party already got an EIN today (limit is one per day) | Wait until the next day and reapply online |
| 115 | The system shows the responsible party as deceased | Contact the IRS with documentation to correct the record |
After your EIN comes through
Once the manual review clears, the IRS issues your EIN and its confirmation letter (CP 575). Keep that letter — it’s the original proof banks and lenders ask for. If you lose it later, you can’t get another CP 575, but the IRS will send a 147C verification letter that serves the same purpose. Our guide to faxing Form SS-4 walks through the full application and both letters.
What does EIN reference number 101 mean?
Can I fix Reference 101 online?
Do I have to change my business name?
How long does it take after I fax Form SS-4?
Should I include my formation documents?
Can I just call the IRS to get my EIN?
Working through other IRS paperwork? See our guide to faxing Form SS-4 for an EIN, our full list of IRS fax numbers, or the guides to Form 2553 and Form 2848.
