How do I verify a vendor's EIN before onboarding them?

To verify a vendor’s EIN before onboarding, use a combination of document review, IRS matching tools, and tax form validation:

1) Collect a completed W-9

Ask the vendor for a signed IRS Form W-9. Check that:

• Legal name matches their business registration
• Tax classification is filled out
• EIN is in the correct format: XX-XXXXXXX
• Address and entity type look consistent

2) Match the EIN against IRS records if available

The IRS does not provide a public EIN lookup for general verification of private businesses. However, you can validate indirectly by:

• Comparing the name + EIN on the W-9 to prior invoices, contracts, or tax documents
• Using IRS TIN Matching if you are a payer required to file information returns (typically via authorized access, often through an IRS-approved channel or tax software/provider)

3) Confirm the business exists

Verify the vendor through independent sources:

• Secretary of State / business registry in the formation state
• Vendor’s website, invoice headers, and contract name
• Dun & Bradstreet or other business credit databases
• Professional licenses or state registrations if relevant

4) Check for consistency across documents

Make sure the following all align:

• Legal entity name
• EIN
• Address
• Business type
• Bank account name for payment

5) Use fraud controls

To reduce risk:

• Require a voided check or bank letter for ACH setup
• Call the vendor using a known business number, not just the contact in the email
• Watch for mismatches like a personal name with a company EIN

6) Keep tax compliance in mind

If the vendor is a U.S. entity and you will pay them $600+ in a year (common threshold for 1099 reporting), you generally need a W-9 on file before payment.

Important limitation

There’s no universal public database where you can simply type in an EIN and confirm ownership. Any “EIN lookup” service claiming broad public verification should be treated cautiously.

If you want, I can give you a vendor onboarding EIN verification checklist or a W-9 review template.