An Employer Identification Number (EIN)—also known as a Federal Employer Identification Number (FEIN)—is a unique nine-digit number assigned by the IRS to identify business entities for tax purposes. While not every business needs an EIN, there are clear scenarios in which having one is required by law.
If your business meets any of the following conditions, you must obtain an EIN:
1. You Have Employees
Any business that hires workers is legally obligated to obtain an EIN. The number is used to report employment taxes, withholdings, and payroll information to the IRS.
2. You Operate as a Partnership or Corporation
Whether or not the business has employees, all partnerships and corporations (including S-Corps and C-Corps) must have an EIN. These business structures are considered separate legal entities, and the IRS requires an EIN to process tax filings appropriately.
3. Your Business Is a Multi-Member LLC
A multi-member Limited Liability Company (LLC) is treated as a partnership for tax purposes unless it elects to be taxed as a corporation. In either case, the IRS mandates an EIN for proper tax reporting.
4. You File Specific Federal Tax Returns
If your business is required to file any of the following tax returns, an EIN is mandatory:
- Employment tax returns (e.g., Form 941, Form 940)
- Excise tax returns (e.g., fuel, environmental taxes)
- Alcohol, tobacco, or firearms tax returns under TTB regulations
5. You Withhold Taxes on Income Paid to Non-Resident Aliens
If you make payments to foreign individuals or entities and are required to withhold U.S. taxes (e.g., on interest, rent, royalties), you need an EIN to properly report and remit those withholdings.
6. You Manage an Estate, Trust, or Nonprofit Organization
Estates (after the death of an individual), trusts, and nonprofit entities like 501(c)(3) organizations are also required to have an EIN to fulfill federal reporting obligations.
Bottom Line
If your business falls into any of these categories, obtaining an EIN is not optional—it’s required for IRS compliance and smooth business operations.