Getting an EIN
An Employer Identification Number (EIN) is the federal tax ID for businesses, partnerships, corporations, trusts, estates and many other organizations — and for sole proprietors who have employees or want a number to give clients instead of their Social Security number. Form SS-4 is the paper application for one.
An EIN is free. Most US-based applicants can get one online on the IRS website and receive the number immediately. The paper SS-4 is the route when the online application isn't available to you — for example, some international applicants — or when you prefer to fax or mail. Be wary of websites that charge to "file your EIN application": they submit the same free form.
What the form asks
The 2-page form has 89 fields. The main ones:
- Lines 1–7 — legal name, trade name, mailing and street address, and the "responsible party" (the person who controls the entity) with their SSN, ITIN or EIN.
- Lines 8–9 — whether it is an LLC (and how many members), and the type of entity.
- Line 10 — why you are applying: starting a business, hiring employees, banking purposes, changing organization type, and so on.
- Lines 11–18 — start date, closing month of the accounting year, expected employees and first wage date, principal activity.
Our editor labels each of these with the text printed on the form, which helps on a form where the boxes are small and dense.
FAQ
How do I submit a paper SS-4?
By fax or by mail, to the IRS address and fax number given in the form's instructions for your situation. Faxed applications are answered faster than mailed ones.
Can I use this form for a sole proprietorship?
Yes — choose "Sole proprietor" on line 9a and provide your SSN as the responsible party.
Which revision is this?
The IRS revision dated December 2025.