Check the business’s W-2, 1099, or tax forms
Review the business’s payroll records or tax filings
Look at the business’s invoices, contracts, or vendor documents
Search the business’s website, especially the footer, legal, or contact pages
Contact the business’s accounting or payroll department
Ask the business owner or authorized representative
Search state business registration records
Use the IRS EIN verification options if you are authorized
Check previous correspondence from the IRS
Review bank account opening documents for the business
Look at loan, credit, or insurance application paperwork
Consult public business filings if the EIN was disclosed there