IRS Form SS-4: Application for Employer Identification Number (EIN)
Form SS-4 is the application for an Employer Identification Number, or EIN, the nine-digit number the IRS uses to identify a business, trust or other entity. Many applicants can get an EIN online at no cost. The IRS sends a confirmation notice once the number is assigned.
What this form is for
It gives the IRS the entity type, responsible party and business details needed to assign an EIN.
When people usually use it
People use it when starting a business, hiring employees, opening a business bank account or forming a trust or estate.
What to have ready
- The legal name and type of entity
- The responsible party's name and Social Security number
- The business address and start date
Notices that mention it
- IRS Notice CP575: Confirmation of your business tax ID number
Related forms
- Form 8822-B: Change of Address or Responsible Party - Business
- Form 2553: Election by a Small Business Corporation
- Form W-9: Request for Taxpayer Identification Number and Certification
- Form 941: Employer's Quarterly Federal Tax Return
Read the IRS page
IRS.gov page for Form SS-4 (opens in a new tab). The IRS page is the final word on this form.
Frequently asked questions
What is IRS Form SS-4?
Form SS-4 is the application for an Employer Identification Number, or EIN, the nine-digit number the IRS uses to identify a business, trust or other entity. Many applicants can get an EIN online at no cost. The IRS sends a confirmation notice once the number is assigned.
Where do I get Form SS-4?
Use the official IRS page, https://www.irs.gov/forms-pubs/about-form-ss-4. Copies from other sites may be out of date, and the IRS page is the final word.
Do I need to file Form SS-4?
There is no single answer. Check the IRS page for Form SS-4 and any letter that asked about it. For advice on your case, talk with a tax professional.
What should I have ready for Form SS-4?
Most people start with: the legal name and type of entity; the responsible party's name and social security number; the business address and start date. The instructions on IRS.gov list everything the form asks for.
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