IRS Form SS-4 - IRS Forms, Instructions, Pubs 2026

IRS Form SS-4 – IRS Forms, Instructions, Pubs 2026 – In today’s business landscape, obtaining an Employer Identification Number (EIN) is a crucial step for entrepreneurs, small business owners, and organizations alike. Whether you’re starting a new venture, hiring employees, or managing tax obligations, IRS Form SS-4 serves as the gateway to securing this essential tax ID. This comprehensive guide will walk you through everything you need to know about Form SS-4, including its purpose, who needs it, step-by-step instructions for completion, submission options, and tips to avoid common pitfalls. We’ll draw from official IRS resources to ensure accuracy and relevance for 2026.

What Is IRS Form SS-4 and Why Do You Need It?

IRS Form SS-4, officially titled “Application for Employer Identification Number,” is the document used to request a nine-digit EIN from the Internal Revenue Service (IRS). An EIN functions like a Social Security Number (SSN) for your business—it’s used for tax filing, reporting, and other federal tax purposes. This number is assigned to various entities, including sole proprietors, corporations, partnerships, estates, trusts, nonprofits, and even certain individuals.

The primary purpose of Form SS-4 is to establish a business tax account with the IRS. You’ll need an EIN if your entity doesn’t already have one but must report it on tax returns, statements, or other documents. For instance, it’s required for opening business bank accounts, applying for business licenses, filing employment taxes, or complying with withholding regulations. Without an EIN, you can’t properly handle payroll, make tax deposits, or file certain forms like Form 941 (Employer’s Quarterly Federal Tax Return) or Form 944 (Employer’s Annual Federal Tax Return).

Key reasons to apply include starting a new business, hiring employees, changing your business structure, or creating a trust or pension plan. Even if you’re a sole proprietor without employees, you might need an EIN for excise taxes, retirement plans, or banking purposes. Note that the form was last revised in December 2025, so always use the most current version to avoid processing delays.

You can download the latest PDF version of Form SS-4 directly from the IRS website: https://www.irs.gov/pub/irs-pdf/fss4.pdf.

Who Needs to File IRS Form SS-4?

Not every individual or entity requires an EIN, but many do. Here’s a breakdown of common scenarios where filing Form SS-4 is necessary:

Business Owners and Employers: If you’re starting a corporation, partnership, or LLC, or if you plan to hire employees (including household workers), an EIN is mandatory for payroll taxes and withholding.
Sole Proprietors: Generally, you can use your SSN, but you’ll need an EIN if you have employees, file excise or employment tax returns, or withhold taxes on non-wage income paid to nonresident aliens.
Trusts and Estates: For irrevocable trusts, estates of decedents, or pension plans, an EIN is required for tax reporting.
Nonprofits and Government Entities: Churches, nonprofits, state/local governments, and Indian tribal enterprises must apply if they engage in taxable activities or have employees.
Foreign Entities and Withholding Agents: International applicants or those complying with IRS withholding rules (e.g., on portfolio assets or treaty benefits) often need an EIN.
Other Cases: If you’re a plan administrator, REMIC (Real Estate Mortgage Investment Conduit), or handling banking purposes like opening accounts that require an EIN.

If your business already has an EIN, you typically don’t need a new one for name changes or address updates—use Form 8822-B instead. However, a new EIN is required for significant changes like incorporating a sole proprietorship or adding partners to form a partnership.

Step-by-Step Guide to Filling Out IRS Form SS-4

Completing Form SS-4 requires accurate information about your entity. The form has 18 lines plus sections for a third-party designee and signature. Type or print clearly, and refer to the separate instructions (available at IRS.gov/FormSS4) for details. Here’s a line-by-line walkthrough:

Legal Name of Entity (Line 1): Enter the exact legal name as it appears on your SSN card, business formation documents, or trust instrument. For individuals, use your full name; for estates, include “Estate” after the decedent’s name.
Trade Name (Line 2): If your business operates under a DBA (doing business as) name different from Line 1, enter it here.
Care Of Name (Line 3): For executors, trustees, or fiduciaries; otherwise, leave blank.

4-5. Addresses (Lines 4a-5b): Provide mailing and physical street addresses. Include foreign details if applicable; no P.O. boxes for physical addresses.

Principal Business Location (Line 6): County and state where your main operations are based.
Responsible Party (Lines 7a-7b): Name and SSN/ITIN/EIN of the person or entity controlling the applicant (e.g., principal officer for corporations). This must be an individual unless it’s a government entity.
LLC Details (Lines 8a-8c): If applying for an LLC, indicate yes/no, number of members, and if organized in the U.S.
Type of Entity (Lines 9a-9b): Check the appropriate box (e.g., sole proprietor, corporation) and provide incorporation details if applicable. For LLCs, follow instructions for classification.
Reason for Applying (Line 10): Select one box, such as “Started new business” or “Hired employees,” and specify details.

11-12. Business Dates (Lines 11-12): Date started/acquired and closing month of your accounting year (e.g., December for calendar year).

13-14. Employees (Lines 13-14): Estimate numbers by category; check Line 14 if you qualify for annual Form 944 filing (liability ≤$1,000/year, or wages ≤$5,000 or ≤$6,536 in territories).

First Wages Paid (Line 15): Date wages or annuities begin; N/A if no employees.

16-17. Business Activity (Lines 16-17): Check principal industry and describe products/services in detail.

Prior EIN (Line 18): Indicate if the entity has ever received an EIN and provide it if yes.
Third-Party Designee: Optional; authorize someone to receive your EIN and handle questions.
Signature: Must be signed by an authorized person under penalties of perjury.

Gather all info beforehand to avoid errors. Common mistakes include using abbreviations on Line 1, selecting multiple reasons on Line 10, or omitting business activity details.

How to Submit Your EIN Application?

The IRS offers multiple ways to apply, but online is the fastest for eligible applicants.

Online Application: Ideal for U.S.-based businesses. Visit IRS.gov/EIN, answer interview-style questions, and receive your EIN immediately if approved. Available certain hours; must complete in one session. Advantages: Free, instant, and no paper form needed.
Fax: Submit signed Form SS-4 to 855-641-6935 (U.S.) or other numbers for territories/international. Expect EIN in about 4 business days.
Mail: Send to IRS EIN Operation in Cincinnati, OH (or international address). Processing takes 4-5 weeks.
Phone: For international applicants only; call 267-941-1099 (6 a.m.-11 p.m. ET).

One EIN per responsible party per day. If you don’t receive your EIN on time, contact the IRS at 800-829-4933.

Tips for a Smooth EIN Application Process

Use Official Sources: Apply directly through IRS.gov to avoid fees from third-party sites.
Keep Records Updated: Report changes via Form 8822-B within 60 days.
Avoid Duplicates: Don’t apply multiple times for the same entity.
For LLCs: Understand default classifications (disregarded entity for single-member) and elect otherwise if needed via Form 8832.
International Applicants: Use phone or fax/mail; provide foreign addresses accurately.
If No EIN by Filing Deadline: Write “Applied For” and the date on your return.

Frequently Asked Questions About IRS Form SS-4

1. How long does it take to get an EIN?

Online: Immediate. Fax: 4 days. Mail: 4-5 weeks.

Yes, if you’re a foreign applicant without an SSN/ITIN, note “foreign” or “N/A” on Line 7b.

3. Do I need a new EIN if my business name changes?

No, update via Form 8822-B unless the structure changes significantly.

4. Is there a fee for an EIN?

No, it’s free from the IRS. Beware of scams charging for this service.

Conclusion

Securing an EIN via IRS Form SS-4 is a straightforward process that sets the foundation for your business’s tax compliance. By following this guide and using the official PDF (https://www.irs.gov/pub/irs-pdf/fss4.pdf), you can apply confidently in 2026. For personalized advice, consult a tax professional or visit IRS.gov for the latest updates. Start your application today and keep your business on track!