What Is a Federal Employee ID Number Used For?

An Employer Identification Number is a nine-digit number assigned by the Internal Revenue Service. It is used by the government to identify a business entity.

If a business employs workers, withholds taxes on income or operates as a corporation or partnership, then the IRS requires the business to obtain an EIN. An EIN is also required for trusts, estates and non-profit organizations, among other entities. An EIN can be obtained by mail, phone or fax; however, the IRS prefers customers to submit applications online. An EIN is assigned immediately after completing the application. The application can be accessed via the IRS website.