Should I attach a blank W-9 PDF to the email?

Avoid blank PDF attachments when you can send a secure request link instead. Attachments get lost, completed incorrectly, and cannot be tracked. If you must attach the IRS form, pair it with a portal link and clear instructions.

What subject line works best for a W-9 request?

Use a direct subject that names your company and the action required — for example, 'Action required: W-9 for [Vendor Name] — [Your Company].' Avoid vague subjects like 'Tax form' that vendors ignore or route to spam.

How many follow-up emails should AP send?

Send an initial request at onboarding, a reminder at seven days if incomplete, and an escalation at fourteen days tied to payment hold policy. Log every send so year-end audits show documented outreach, not ad-hoc chasing.

Can procurement send the W-9 request instead of AP?

Yes, if procurement owns vendor onboarding — but the email should come from a monitored mailbox or system address so submissions and reminders are not lost when a buyer leaves. AP should still validate the returned form.

Guide

How to Send a W-9 Request Email

By Keelstar Team · Updated July 11, 2026

The short answer

Send a W-9 request email that explains why you need the form, links to a secure submission portal instead of attaching a blank PDF, states your deadline relative to first payment, and names a contact for entity-structure questions. Keep the email short, professional, and free of unnecessary tax jargon. Never ask vendors to reply with completed W-9s containing SSNs in plain email if your policy prohibits it — route them to a secure upload or e-signature flow and log when the request was sent, opened, and completed.

What a good W-9 request email includes

The email should answer three vendor questions in plain language: why you need the form, how to submit it, and what happens if they miss the deadline. Reference your company name, the vendor's legal name as you have it on file, and the relationship — new vendor, annual refresh, or corrected form after a TIN mismatch.

One-sentence explanation of 1099 reporting and IRS requirements
Secure link to complete and sign the W-9
Deadline tied to first invoice or payment release
Contact email or phone for entity-type questions
Statement that incomplete forms delay payment

Sample structure (not legal advice)

Open with context, state the requirement, provide the link, set the deadline, and close with a contact. Example framing: 'Before we can process payment, we need a completed IRS Form W-9 for [Legal Name]. Use the secure link below to submit — it takes about five minutes. We need this by [date] to release your first invoice.' Adjust tone for your vendor base but keep the compliance requirement explicit.

Security rules for email-based collection

W-9s contain SSNs and EINs. If your information security policy restricts tax data in email, do not invite vendors to reply with completed forms attached. Use a portal that encrypts uploads, captures e-signatures, and timestamps receipt. CC'ing multiple internal recipients on vendor replies spreads SSN exposure — route submissions to a controlled system instead.

Coordinating with payment holds

The request email should align with your AP policy: if payment is blocked until W-9 validation passes, say so upfront. Vendors take the request more seriously when the consequence is concrete. Coordinate wording with procurement so buyers do not promise payment while AP is still waiting on tax documentation.

Tracking sends and responses

Manual Outlook threads do not scale. Use a workflow that records send date, reminder count, submission date, and validation status per vendor ID. When December arrives, you should run a report — not search inboxes — to see who was contacted and who never opened the request.

When to escalate beyond email

High-dollar vendors, law firms, and sole proprietors with SSNs on the line may need a phone call after two unanswered emails. Document the call. For vendors with a history of non-response, escalate to tax leadership before year-end — not after the 1099 filing window closes.

Frequently asked questions

Should I attach a blank W-9 PDF to the email?: Avoid blank PDF attachments when you can send a secure request link instead. Attachments get lost, completed incorrectly, and cannot be tracked. If you must attach the IRS form, pair it with a portal link and clear instructions.
What subject line works best for a W-9 request?: Use a direct subject that names your company and the action required — for example, 'Action required: W-9 for [Vendor Name] — [Your Company].' Avoid vague subjects like 'Tax form' that vendors ignore or route to spam.
How many follow-up emails should AP send?: Send an initial request at onboarding, a reminder at seven days if incomplete, and an escalation at fourteen days tied to payment hold policy. Log every send so year-end audits show documented outreach, not ad-hoc chasing.
Can procurement send the W-9 request instead of AP?: Yes, if procurement owns vendor onboarding — but the email should come from a monitored mailbox or system address so submissions and reminders are not lost when a buyer leaves. AP should still validate the returned form.

Related guides

Put this into a monitored workflow

W-9 Collector handles this continuously — with reminders and an audit trail.

Explore W-9 Collector See the workflow