How to Request a W-9 from a New Vendor

Request the W-9 before first payment

IRS rules expect you to obtain the payee's TIN and certification before making reportable payments. In practice, that means the W-9 request is part of vendor setup — not a year-end afterthought. AP, procurement, and legal should agree: no payment until tax documentation is complete or a documented exception is approved.

What to send (and what to avoid)

Send a secure link to a structured W-9 request prefilled with your company as the requester. Avoid emailing blank IRS PDFs — they get lost, completed incorrectly, and cannot be tracked.

• Use a secure portal or request link per vendor
• Include a short explanation of why the form is required
• State the deadline relative to first invoice or work start
• Provide a contact for vendors who have entity-structure questions
• Never collect SSNs via unencrypted email if your policy prohibits it

Information to confirm on the returned W-9

When the vendor submits, verify: line 1 legal name matches your vendor master and contract; address is current; federal tax classification is marked; TIN is present and formatted correctly; exempt payee and FATCA codes are completed if applicable; and the form is signed and dated. Reject incomplete submissions with specific feedback — not a generic 'please fix.'

Coordinate with procurement and AP

Procurement may onboard the vendor in your ERP before AP sees an invoice. Align systems so vendor status shows 'W-9 pending' until validated. Invoice approval workflows should surface the tax document status — especially for new vendors under SOX or grant-compliance scrutiny.

Vendor master setup

Enter the legal name and TIN from the W-9 into your ERP — not from the first invoice header. Mismatches between vendor master, W-9, and 1099 are a top cause of CP2100 notices. Link the stored W-9 PDF or submission record to the vendor ID.

Keep the audit trail from request to approval

Record when the request was sent, when the vendor opened or submitted, who validated the form, and when payment was released. If a auditor asks whether you had a valid W-9 before a specific payment, you should answer from system history — not from someone's inbox search.