Introduction
You filled out Form SS-4, clicked submit, and instead of your EIN… you got an error code.
Or worse—weeks passed with no response.
Most EIN application problems come from a handful of preventable mistakes. The IRS doesn’t explain these well, so people make the same errors over and over.
This guide covers the 10 most common Form SS-4 mistakes, why they trigger rejections, and exactly how to avoid them. If you’ve already hit an error, I’ll show you how to fix it.
Why Form SS-4 Errors Matter
IRS Form SS-4 is the application for an Employer Identification Number (EIN). You need an EIN to:
- Open a business bank account
- Hire employees
- File certain tax returns
- Apply for business credit or loans
A rejected or delayed application doesn’t just waste time—it can stall your entire business launch. Banks won’t open accounts. Payroll can’t run. Contracts sit unsigned.
The good news: most errors are easy to avoid once you know what causes them.
The 10 Most Common Form SS-4 Mistakes
1. Business Name Doesn’t Match State Records
What happens: Your application triggers Reference Number 101, or the IRS manually rejects it.
Why it happens: The IRS compares your business name against its records. Any mismatch—even minor—can flag your application.
Common variations that cause problems:
| What You Entered | What’s On File | Result |
|---|---|---|
Acme Consulting | Acme Consulting LLC | ❌ Rejected |
ACME CONSULTING LLC | Acme Consulting LLC | ❌ May flag |
Acme Consulting, LLC | Acme Consulting LLC | ❌ Punctuation mismatch |
How to avoid it: Pull up your Articles of Organization or Certificate of Formation. Enter the name exactly as it appears—including “LLC,” commas, periods, and capitalization.
2. Wrong Entity Type on Line 9a
What happens: The IRS processes your EIN under the wrong tax classification, causing problems when you file taxes.
Why it happens: The entity type options are confusing, especially for single-member LLCs.
The correct answer for single-member LLCs:
For most single-member LLCs, select “Sole Proprietor” on Line 9a.
Wait—sole proprietor? Yes. The IRS treats single-member LLCs as “disregarded entities” by default. For tax purposes, you and your LLC are the same person.
Exception: If you’re getting an EIN specifically for employment taxes, excise taxes, or Form 5472 (foreign-owned LLCs), check “Other” and write “Disregarded entity” in the space provided.
Common wrong answers:
- Selecting “Corporation” (only if you’ve filed Form 8832 to elect corporate taxation)
- Selecting “Partnership” (only for multi-member LLCs)
- Leaving it blank
3. Responsible Party Information Doesn’t Match IRS Records
What happens: Reference Number 102 or 103 appears, blocking your application.
Why it happens: The name and SSN/ITIN you entered don’t match what the Social Security Administration has on file for that person.
This is the #1 cause of instant rejections on online applications.
Common causes:
- Typos in SSN or ITIN
- Using a maiden name instead of legal name
- Middle name variations (using “J” when records show “James”)
- Recently changed name not yet updated with SSA
How to avoid it:
- Use your name exactly as it appears on your Social Security card
- Double-check every digit of your SSN
- If you recently changed your name, update it with SSA first
Important since 2018: The responsible party must be an individual person with an SSN or ITIN. You cannot list a business entity or use another company’s EIN here.
4. Third-Party Designee Has Same Contact Info as Business
What happens: Reference Number 104 appears.
Why it happens: If you authorized someone else (accountant, attorney, filing service) to receive your EIN, their contact information cannot match the business’s address or phone number.
The IRS requires the third-party designee to have separate contact details.
How to avoid it: Either:
- Leave the Third-Party Designee section blank (you’ll receive the EIN yourself), or
- Ensure the designee’s address and phone are completely different from your business
5. Applying for Multiple EINs in 24 Hours
What happens: Reference Number 114 appears.
Why it happens: The IRS limits each responsible party to one EIN per day. This prevents fraud and duplicate applications.
Even if your first application had an error, you can’t immediately try again with the same SSN.
How to avoid it: Wait 24 hours before reapplying. If you need EINs for multiple businesses, apply on different days or use different responsible parties.
6. Applying Before Your LLC Is Formed
What happens: Reference Number 101 or rejection.
Why it happens: The IRS checks whether your business exists at the state level. If your LLC isn’t officially registered yet, there’s nothing to match.
How to avoid it: Wait until you receive confirmation from your state (typically your stamped Articles of Organization) before applying for an EIN.
Note: Louisiana and West Virginia have special rules. Check your state’s requirements.
7. Using the Wrong Business Start Date
What happens: May not cause immediate rejection, but creates IRS record inconsistencies that cause problems later.
Why it happens: People enter “today’s date” without checking their actual formation date.
The correct answer: Enter the date your LLC was officially formed by the state, or the date you acquired an existing business.
If your LLC was approved on December 15, 2024, but you chose January 1, 2025 as your effective date, use January 1, 2025.
8. Leaving Required Fields Blank
What happens: Application goes into manual review, adding weeks to processing time.
Why it happens: Some fields look optional but aren’t. The online application forces completion, but paper Form SS-4 submissions often arrive incomplete.
Commonly skipped fields that cause problems:
- Line 8b (number of LLC members)
- Line 8c (state where LLC was organized)
- Line 10 (reason for applying)
- Line 16 (principal business activity)
How to avoid it: Review every line before submitting. If a field doesn’t apply, confirm that it’s actually optional rather than assuming.
9. Submitting Paper When Online Is Available
What happens: 4-6 week delay instead of instant approval.
Why it happens: Some people don’t realize the online option exists, or they assume paper is “safer.”
The reality:
| Method | Processing Time |
|---|---|
| Online | Immediate (EIN issued within minutes) |
| Fax | 4 business days |
| 4-6 weeks |
The online application is available Monday–Friday, 7 AM–10 PM Eastern at irs.gov.
When you must use paper: International applicants without a US address, or anyone who receives Reference Number 101 (requires manual review).
10. Not Saving the Confirmation Letter
What happens: You get your EIN but lose the CP 575 confirmation letter—then discover banks and licensing agencies need it.
Why it happens: The online application gives you one chance to download/print your confirmation. If you miss it or have technical issues, you’ll wait 30 days before you can request a replacement (147C letter).
How to avoid it:
- Before starting the application, have a printer ready or know how to save PDFs
- Immediately download and save the CP 575 letter when it appears
- Save it in multiple places (computer, cloud storage, email to yourself)
IRS Error Codes Explained
If your online application fails, you’ll see a reference number. Here’s what they mean:
| Code | Meaning | Solution |
|---|---|---|
| 101 | Business name matches or is too similar to existing entity | File Form SS-4 by fax (855-641-6935) with your formation documents |
| 102 | SSN/ITIN doesn’t match responsible party name | Double-check info and retry, or file Form SS-4 by fax/mail |
| 103 | EIN/company name mismatch (entity listed as responsible party) | Responsible party must be an individual, not a business |
| 104 | Third-party designee has same contact info as business | Use different contact info or remove third-party designee |
| 105 | Too many failed attempts today | Wait 24 hours and try again |
| 109–113 | IRS technical issues | Wait and retry, or file Form SS-4 by fax/mail |
| 114 | Already received an EIN today | Wait 24 hours |
| 115 | Responsible party shows as deceased in IRS records | Contact IRS at 800-829-4933 |
What to Do If You Made a Mistake
Already submitted Form SS-4 with errors? Here’s how to fix it:
If you haven’t received your EIN yet:
- Online applications with errors usually fail immediately with a reference code
- Paper applications may be rejected or processed with incorrect info
- If rejected, correct the errors and resubmit
If you received an EIN with wrong information:
- Minor corrections: Call the IRS Business & Specialty Tax Line at 800-829-4933
- Name changes: File a letter on business letterhead with old and new information
- Address changes: File Form 8822-B (Change of Address)
- Major changes (like entity type): May require a new EIN
Important: Some mistakes can’t be easily corrected. If your EIN was issued with the wrong entity classification, you may need to apply for a new EIN entirely.
Frequently Asked Questions
Will the IRS reject my application if I make a mistake?
It depends on the mistake. Name mismatches and SSN errors usually trigger immediate rejection with a reference code. Other errors may result in an EIN being issued with incorrect information—which causes problems later.
Can I correct mistakes after receiving my EIN?
Yes, but the process varies. Simple corrections (typos, address changes) can often be made with a phone call. Structural changes may require additional forms or a new EIN.
How long does it take to fix EIN errors?
Phone corrections can be immediate. Written corrections take 4-6 weeks. If you need to reapply, add another 4-6 weeks for paper applications.
Can someone else fill out Form SS-4 for me?
Yes, but the responsible party must be correctly identified (not the preparer), and if you use a third-party designee, their contact info must differ from your business’s.
Is it better to apply online or by paper?
Online is almost always better—instant approval, fewer errors, immediate confirmation. Use paper only if you’re required to (international applicant) or your online application was rejected with Reference Number 101.
The Easier Way to Avoid SS-4 Mistakes
Form SS-4 isn’t complicated once you understand it—but the IRS doesn’t make understanding it easy.
If you’d rather skip the confusing form and avoid these mistakes entirely, FillMyForm.app walks you through the process with simple questions. No IRS jargon, no guessing which box to check. Just answer questions about your business, and get your form filled out correctly the first time.
→ Complete Form SS-4 the easy way
Last updated: January 2025. Information verified against current IRS Form SS-4 instructions (Rev. December 2025) and official IRS guidance.