Free IRS form · Official PDF

Form SS-4: Application for Employer Identification Number

Current IRS revision · Download free — no email, no account

An EIN is your business's Social Security number — you'll need it to open a bank account, hire employees, or form an LLC that doesn't run on your personal SSN. Form SS-4 is the application. Download it free, or see why most people skip the paper entirely.

Form SS-4 — Application for Employer Identification Number

Free · Official IRS PDF · Current IRS revision · Print-ready
↓  Download Form SS-4 (PDF) Instructions: irs.gov

What is Form SS-4?

Form SS-4, Application for Employer Identification Number, is how businesses, estates, and trusts request an EIN — the nine-digit number the IRS uses to identify a business entity. Despite the "Employer" in the name, you don't need employees to need one.

Here's the practical secret: the paper SS-4 is the slow lane. The IRS issues EINs instantly and free online for applicants with a U.S. taxpayer ID. The paper/fax form still matters for international applicants, entities whose responsible party has no SSN/ITIN, and anyone who prefers a written record — and the online interview follows the SS-4's structure, so understanding the form helps either way.

Who files Form SS-4?

  • New LLCs, corporations, and partnerships — multi-member entities are required to have an EIN.
  • Sole proprietors who hire employees, open a solo 401(k), or simply want to keep their SSN off W-9s.
  • Anyone opening a business bank account — nearly every bank requires an EIN for entity accounts.
  • Estates and trusts that need to file their own returns after a death.

Deadlines

There's no deadline — you apply when you need one. Timing tip: get the EIN after your LLC or corporation is formed with the state, so the entity name on the EIN matches. Online applications issue immediately; fax takes about 4 business days; mail takes 4+ weeks.

How to fill out Form SS-4

  1. Lines 1–7 — identify the entity

    Legal name (exactly as formed with the state), trade name, mailing address, and the responsible party — the human who controls the entity, with their SSN or ITIN.

  2. Lines 8–9 — entity type

    LLC member count, and the tax classification checkbox: sole proprietor, partnership, corporation, estate, trust, etc.

  3. Line 10 — reason for applying

    "Started new business" is most common; banking purposes, hiring employees, and estate administration are others.

  4. Lines 11–17 — business details

    Start date, closing month of accounting year, expected employees, and principal activity.

  5. Sign and submit

    Online for an instant EIN, or fax/mail the signed form. One EIN per responsible party per day is the IRS limit.

Form SS-4 — frequently asked questions

Yes — completely free, directly from the IRS. Third-party sites charge $50–$300 for the same thing. Apply online at irs.gov or file the SS-4 by fax or mail at no cost.
Not always for taxes — a disregarded single-member LLC can often use the owner's SSN. But you'll need an EIN to open a business bank account at most banks, and most owners get one anyway to keep their SSN private on W-9s.
The individual who ultimately owns or controls the entity — not a registered agent or formation service. The IRS requires a real person with an SSN or ITIN for online applications, and you must update it via Form 8822-B within 60 days if it changes.
Instantly, if you apply online during IRS operating hours. Fax applications take about 4 business days; mailed SS-4s can take 4–6 weeks.

Related IRS forms

Form W-9Request for Taxpayer Identification Number and CertificationForm 8822-BChange of Address or Responsible Party — BusinessSchedule CProfit or Loss From Business (Sole Proprietorship)

Forming an LLC? The EIN is step two.

Step one is the paperwork — and step three is the operating agreement your bank will ask for. BizDocs creates LLC operating agreements in about ten minutes.

Create an LLC operating agreement
Important: BizDocs is not affiliated with or endorsed by the Internal Revenue Service. The forms offered on this page are official, unmodified IRS documents provided free as a public resource; the IRS publishes them in the public domain at irs.gov. The guides on this page are general information, not tax or legal advice — tax rules change and depend on your situation, so verify details in the official IRS instructions or with a qualified tax professional before filing.