Employer Tax Identification Number Law and Legal Definition

The employer tax identification number is a 9-digit state identification number, e.g., 12-3456789, assigned to each employer by the Internal Revenue Service (IRS). This number must be used on all documentation submitted to the agency. In some states, the EIN is the same as the Federal Employer Identification Number (FEIN). EINs are used by employers, sole proprietors, corporations, partnerships, nonprofit associations, trusts, estates of decedents, government agencies, certain individuals, and other business entities.

You are required to have an EIN if you operate your business as a corporation or a partnership, have employees, have a Keogh plan, file Employment, Excise, or Alcohol, Tobacco and Firearms tax returns, withhold taxes on income, other than wages, paid to a non-resident alien, or are involved with any of the following types of organizations:

  • Trusts, except certain grantor-owned revocable trusts, IRAs, Exempt Organization Business Income Tax Returns
  • Estates
  • Real estate mortgage investment conduits
  • Non-profit organizations
  • Farmers' cooperatives
  • Plan administrators