Employer Identification Number (EIN)

An Employer Identification Number (EIN) is a unique nine-digit number assigned to U.S. business entities. The EIN is also known as Federal Employer Identification Number (FEIN) or Federal Tax Identification Number (FTIN). An EIN is unique to the business entity to which it was assigned, and it never expires. The same number set is never reissued to another business entity, even if it goes bankrupt and gets winded up.

Business entities may freely apply for an EIN online, by phone, fax, or mail. The application must be filed after the business entity has been formally created but before it begins day-to-day operations. The applicant can request an EIN by filling out Form SS-4, and at least the following information needs to be provided in the application: 

  • The type of business entity.
  • The reasons for applying (new business, change of organization, IRS withholding requirement compliance).
  • The start or acquisition date.
  • The principal industry of the business.

The Internal Revenue Service (IRS) uses the EIN to identify businesses for tax reporting and compliance. Additionally, business entities will require the EIN for the following purposes:

  • Hiring and paying employees.
  • Opening bank accounts and obtaining loans.
  • Filing taxes.

The following business entities mandatorily require an EIN:

Please visit the IRS webpage for further information about the EIN.

[Last updated in November of 2021 by the Wex Definitions Team]