Help: Where can I get a Federal Employer Identification Number (FEIN)? ← Unemployment - Employers The Internal Revenue Service (IRS) issues Federal Employer Identification Numbers (FEIN). Applications may be completed online OR you can request form SS-4 (FEIN application) and instructions by calling the IRS at 1-800-TAX-FORM (1-800-829-3676).The IRS also provides information on the Internet about who must have an FEIN and how to get one. See the IRS website for other helpful employer tax information.