Check your IRS EIN confirmation letter
Look at prior federal tax returns
Review business bank account documents
Check payroll or tax filing records
Search business formation paperwork
Contact your bank or accountant
Call the IRS Business & Specialty Tax Line at 800-829-4933
Use the IRS online EIN application records if you applied online
Check state or local business license documents
Review any loan, credit, or vendor applications that asked for your EIN