SS-4 Form Online Application – How to Fill Out and Submit IRS Form SS-4?

SS-4 Form Online Application – Are you starting a new business, hiring employees, or managing a trust? Obtaining an Employer Identification Number (EIN) is a crucial step, and IRS Form SS-4 is the key document for this process. In this comprehensive guide, we’ll walk you through everything you need to know about the SS-4 form online application, including eligibility, a step-by-step breakdown of how to fill it out, and submission options. Whether you’re a sole proprietor, corporation, or nonprofit, applying for an EIN online can be quick and straightforward, often providing your number instantly.

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

IRS Form SS-4, officially titled “Application for Employer Identification Number (EIN),” is used to request a unique 9-digit number for tax purposes. This EIN acts like a Social Security Number for your business or entity, required for filing taxes, opening bank accounts, hiring employees, and more. It’s essential for sole proprietors, corporations, partnerships, estates, trusts, and other entities engaging in business activities.

You need an EIN if:

  • You’re starting a new business.
  • Hiring employees (even if you’re a sole proprietor).
  • Operating as a corporation or partnership.
  • Managing a trust, estate, or pension plan.
  • Withholding taxes on non-wage income paid to nonresident aliens.
  • Changing your business structure or for banking purposes.

Note that an EIN is for business use only and cannot replace a Social Security Number (SSN) or Individual Taxpayer Identification Number (ITIN). Recent updates include the reinstatement of the option on Line 14 to elect filing Form 944 annually for small employers, effective as of March 2024.

Eligibility for Online EIN Application

The online SS-4 application is the fastest way to get your EIN, but not everyone qualifies. To apply online:

  • Your principal place of business, office, or legal residence must be in the U.S. or U.S. territories.
  • You must be the responsible party (e.g., owner, principal officer, or authorized representative) with a valid SSN, EIN, or ITIN.
  • Third-party designees can apply if they have signed authorization.

International applicants or those without a U.S. presence must use phone, fax, or mail methods. There’s a daily limit: only one EIN per responsible party per day.

How to Fill Out IRS Form SS-4? (Step-by-Step Guide)

Filling out Form SS-4 requires accurate information to avoid delays. The form is revised as of December 2025, so use the latest version from the IRS website. Enter “N/A” for inapplicable lines, and type or print clearly. Below is a detailed breakdown of each line based on official instructions.

Basic Entity Information (Lines 1-6)

  • Line 1: Legal name of entity (or individual) – Enter the exact legal name from your SSN card, charter, or other legal documents. For sole proprietors, use your full name; for trusts, the name from the trust instrument.
  • Line 2: Trade name (DBA) – If your business operates under a different name, enter it here.
  • Line 3: Executor, administrator, trustee, or “care of” name – For trusts or estates, enter the relevant fiduciary’s name.
  • Lines 4a-4b: Mailing address – Provide the address for IRS correspondence, including city, state, ZIP, and country (if foreign).
  • Lines 5a-5b: Street address – Enter the physical location if different from mailing (no P.O. boxes).
  • Line 6: County and state of principal business – Specify the primary location.

Responsible Party Details (Lines 7a-7b)

  • Line 7a: Name of responsible party – Enter the full name of the individual who controls the entity’s funds (e.g., owner or principal officer). Must be a person, not an entity (except for government entities).
  • Line 7b: SSN, ITIN, or EIN – Provide the responsible party’s tax ID. Enter “N/A” if ineligible.

LLC-Specific Information (Lines 8a-8c)

  • Line 8a: Check “Yes” if applying for an LLC; otherwise, “No.”
  • Line 8b: If yes, enter the number of members.
  • Line 8c: Check if the LLC was organized in the U.S.

Entity Type and Details (Lines 9a-9b)

  • Line 9a: Type of entity – Check one box (e.g., Sole proprietor, Partnership, Corporation). For disregarded entities like single-member LLCs, check “Other” and specify. Include any form number for corporations (e.g., Form 1120).
  • Line 9b: If a corporation, enter the state or foreign country of incorporation.

Reason and Business Dates (Lines 10-12)

  • Line 10: Reason for applying – Check one (e.g., Started new business) and specify details.
  • Line 11: Date business started or acquired – Enter the month, day, year.
  • Line 12: Closing month of accounting year – Typically “December” for calendar year.

Employment and Tax Details (Lines 13-15)

  • Line 13: Highest number of employees expected – Enter numbers for agricultural, household, or other (0 if none).
  • Line 14: Check if you want to file Form 944 annually (for expected tax liability ≤$1,000/year).
  • Line 15: First date wages paid – Enter the date; “N/A” if no employees.

Business Activity (Lines 16-17)

  • Line 16: Principal activity – Check the best description (e.g., Retail, Manufacturing).
  • Line 17: Provide a detailed description of products, services, or work (e.g., “Residential construction contracting”).

Prior EIN and Third-Party Designee (Line 18 and Section)

  • Line 18: Check if the entity previously had an EIN and provide it.
  • Third-party designee: Optional; authorize someone to receive your EIN and answer questions.

Signature

Sign as the responsible party (e.g., owner or officer) and include your title, date, and contact info.

For visual reference, here’s a sample of a partially filled Form SS-4:

How to Submit IRS Form SS-4?

The IRS offers multiple free submission methods, with online being the quickest.

Online Submission (Recommended)

  • Visit the IRS EIN application page and complete the interactive questionnaire in one session (it times out after 15 minutes of inactivity).
  • Available Monday-Friday 6 a.m. to 1 a.m. ET, Saturday 6 a.m. to 9 p.m. ET, Sunday 6 p.m. to midnight ET.
  • Receive your EIN immediately if approved; print the confirmation.

Other Methods

  • Phone (International only): Call 267-941-1099 (6 a.m. to 11 p.m. ET, Mon-Fri).
  • Fax: Send to 855-641-6935 (U.S.) or appropriate international number; get EIN in ~4 business days.
  • Mail: Send to IRS EIN Operation in Cincinnati, OH; processing takes 4-5 weeks.

Use only one method to avoid duplicates.

Common Mistakes to Avoid and Pro Tips

  • Incomplete information: Double-check all lines; omissions delay processing.
  • Wrong entity type: Ensure Line 9a matches your structure to avoid tax classification issues.
  • Changes after submission: Use Form 8822-B for updates to responsible party or address within 60 days.
  • Paying fees: EINs are free; avoid scam sites charging for the service.
  • Preparation: Gather all details beforehand, especially for online applications.
  • For LLCs: If electing corporate status, file Form 8832 separately.

If you’re forming an entity, complete state registration first to prevent delays.

Applying for an EIN via the SS-4 form online is efficient and free, setting your business up for tax compliance in minutes. Always download the latest form and instructions from the IRS to stay current. If you encounter issues, contact the IRS at 800-829-4933. With your EIN in hand, you’re ready to tackle business taxes, payroll, and growth opportunities. Start your application today!