Guide
How to Collect W-9s from Vendors
By Keelstar Team · Updated June 1, 2026
The short answer
Send each vendor a single secure request for their W-9, validate the form before you accept it, and keep every version on file with a timestamp. Don't collect W-9s as email attachments — they go stale and scatter. Request, validate, store, and monitor.
Why W-9 collection breaks down
Most teams collect W-9s by emailing a blank form and hoping it comes back complete. It often doesn't: the TIN is missing, the signature is blank, or the form is the wrong year. Then it lives as an attachment in one person's inbox, impossible to find when finance or an auditor asks.
A reliable W-9 collection process
Make the process repeatable so it survives volume and turnover.
- Send one secure request link per vendor — no blank attachments.
- Validate the TIN format, legal name, and signature before accepting.
- Store the signed W-9 with a timestamp and version history.
- Re-request when the form goes stale or the entity changes.
When to move off manual collection
If you collect more than a handful of W-9s, or you need to prove you held a valid W-9 on a given date, move the workflow into a tool that monitors and audits it for you. That's exactly what W-9 Collector does.
Put this into a monitored workflow
W-9 Collector handles this continuously — with reminders and an audit trail.