Check your IRS CP 575 notice or any IRS correspondence
Review your business tax returns (Form 1120, 1120-S, 1065, 1041) for the EIN
Look on your business bank statements or account documents
Check your state tax registrations or business license paperwork
Search your payroll service documents (e.g., ADP, Paychex) for the EIN
Look at your business formation documents (LLC/Corporation filings) if the EIN is listed
Check your W-2/W-3 or 1099 forms issued as the employer
Contact your bank or payroll provider and request the EIN on file
If you have access to your IRS account, sign in and review your EIN-related documents
Call the IRS Business & Specialty Tax Line and ask for EIN verification (have identifying information ready)