Guide
How to Collect W-9s from Vendors
By Keelstar Team · Updated June 1, 2026
The short answer
Before you pay a U.S. vendor, send a single secure W-9 request, validate the TIN and signature on receipt, and store the signed form with a timestamp. Do not rely on email attachments or shared folders — they go stale, get overwritten, and fail audits. Request, validate, store, and re-collect on a schedule.
Why W-9 collection breaks down
Most AP and vendor onboarding teams start by emailing a blank IRS Form W-9. The form comes back incomplete — missing TIN, wrong entity type, no signature, or an outdated revision. It lands in someone's inbox, gets forwarded, and disappears when that person leaves. At year-end, finance scrambles for TINs before 1099 filing, or worse, discovers gaps after filing.
Who needs a W-9 in the U.S.
U.S. persons and U.S. entities you pay for services, rent, or other reportable amounts generally complete Form W-9. Foreign persons and entities use the W-8 series instead. If you are unsure, confirm tax status before the first payment — the wrong form drives incorrect 1099 reporting and withholding.
- Domestic LLCs, corporations, partnerships, and sole proprietors → W-9
- Foreign vendors → W-8BEN or W-8BEN-E (not W-9)
- Individuals paid as independent contractors → W-9 with SSN or ITIN
A reliable W-9 collection process
Make collection repeatable so it survives volume, turnover, and audits.
- Send one secure request link per vendor — never a blank PDF attachment.
- Validate TIN format, legal name, federal tax classification, and signature before accepting.
- Store the signed W-9 with a received date and version history.
- Block or flag payment if W-9 is missing, incomplete, or stale.
- Re-request when the entity changes, the form ages out, or IRS rules update.
What to validate on every W-9
A signed PDF is not enough if the fields are wrong. At minimum confirm: legal name matches how you will pay and report; TIN type (SSN vs EIN) matches entity type; address is current; signature and date are present; and exempt payee / FATCA codes are completed when applicable.
How this connects to 1099 filing
The W-9 is the source of truth for Box names and TINs on Form 1099-NEC and 1099-MISC. Gaps discovered in January are expensive — corrected filings, B-notices, and vendor friction. Collecting clean W-9s at onboarding is cheaper than fixing TIN mismatches after payments are made.
When to move off manual collection
If you onboard more than a handful of vendors per month, operate in a regulated industry, or need to prove you held a valid W-9 on a specific payment date, spreadsheets and inbox searches will fail. A monitored workflow validates on intake, reminds owners before payments, and exports an audit trail on demand.
Frequently asked questions
- Do I need a W-9 before the first payment?
- Yes. You need the payee's TIN and certification before you pay them, so you can report correctly and avoid backup withholding where it applies.
- Can I accept a W-9 by email?
- You can receive it electronically if your process captures a valid signature and you can prove what was on file on a given date. Email attachments alone are hard to audit.
Related guides
Put this into a monitored workflow
W-9 Collector handles this continuously — with reminders and an audit trail.