What is Form SS-4?
Form SS-4 (Application for Employer Identification Number) Form SS-4 is used to apply for an Employer Identification Number (EIN) from the IRS. An EIN is a 9-digit number (XX-XXXXXXX) that identifies a business entity for tax purposes. It's the business equivalent of a Social Security Number. Every US LLC needs an EIN, regardless of whether it has employees.
| Detail | Information |
|---|---|
| Official Name | Application for Employer Identification Number |
| Filing Deadline | No deadline — apply when you need the EIN. Can apply before or after entity formation. Processing: online (immediate for US persons), phone (same day for international), fax (4 business days), mail (4-6 weeks). |
| Penalty for Non-Filing | No penalty for late application, but you cannot open a bank account, file tax returns, or hire employees without an EIN. |
| Filed With | IRS |
Who Needs to File Form SS-4?
Any business entity (LLC, corporation, partnership, trust) that needs an Employer Identification Number for tax filing, banking, or hiring purposes. Non-residents forming US LLCs must obtain an EIN.
Non-Resident Relevance
If you are a non-resident entrepreneur with a US LLC or US-source income, Form SS-4 may be a critical part of your US tax compliance. Consult with a qualified tax professional to determine if this form applies to your situation.
Filing Deadline
No deadline — apply when you need the EIN. Can apply before or after entity formation. Processing: online (immediate for US persons), phone (same day for international), fax (4 business days), mail (4-6 weeks).
Filing on time is critical. If you need more time, file Form 7004 for an automatic 6-month extension before the original due date. Note that an extension of time to file is not an extension of time to pay.
Penalties for Non-Compliance
Penalty Warning
No penalty for late application, but you cannot open a bank account, file tax returns, or hire employees without an EIN.
The IRS enforces these penalties strictly, especially for information returns related to foreign-owned entities. In many cases, there is no reasonable cause exception, making timely filing essential.
How to Complete Form SS-4
Here is a section-by-section breakdown of Form SS-4:
Lines 1-3 – Entity Information
Legal name of entity, trade name (if different), and the responsible party's name and SSN/ITIN.
Lines 4-6 – Address
Mailing address and business address (street address).
Lines 7-8a – Entity Type
Type of entity (LLC, corporation, partnership, etc.) and reason for applying (started new business, hired employees, banking purposes, etc.).
Lines 8b-10 – Additional Details
State of organization, date business started or acquired, closing month of accounting year.
Lines 11-17 – Employment Information
First date wages paid, highest number of employees expected, principal business activity, and NAICS code.
Filing Tip
Given the complexity and steep penalties associated with Form SS-4, we strongly recommend working with a qualified tax professional who has experience with non-resident tax filings. Errors or omissions can trigger significant penalties.
Common Mistakes to Avoid
These are the most frequent errors we see when clients attempt to file Form SS-4 on their own:
- Non-residents trying to apply online (only available to those with SSN/ITIN; international applicants must use phone, fax, or mail)
- Entering the wrong responsible party (should be a principal officer, general partner, or grantor)
- Selecting the wrong entity type
- Not having formation documents ready when calling the IRS
- Applying for multiple EINs for the same entity
- Using an old address and not receiving the EIN confirmation letter
Need Help Filing Form SS-4?
Our tax experts specialize in preparing and filing Form SS-4 for non-resident entrepreneurs. Avoid costly penalties — let us handle it.
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