Guide
How to Collect Vendor Documents in One Place
By Keelstar Team · Updated July 11, 2026
The short answer
Designate one system — vendor portal or compliance platform — as the intake point for W-9s, COIs, contracts, questionnaires, and banking letters. Configure document types with required fields, expiration rules, and validation owners. Disable ad-hoc email submission for tax and banking where policy requires secure upload. Link each uploaded file to the vendor master ID automatically via portal invitation codes or ERP vendor numbers. Train buyers to redirect vendors to the portal instead of accepting attachments. Monthly audit: sample new vendors and confirm every required document lives in the central record — not scattered across three inboxes.
Document type catalog
Define each acceptable document type, file format, max age, and renewal frequency. Ambiguous 'upload insurance' requests produce wrong files. Be specific: ACORD 25 COI, signed W-9, void check or bank letter.
Single intake, multiple reviewers
Vendors upload once; workflows route copies to functional reviewers without re-requesting. Vendors hate sending the same COI to procurement and AP separately.
Naming and version control
Auto-name files with vendor ID, document type, and received date. When vendors upload corrections, supersede prior versions — do not delete without retention policy compliance.
Integration with ERP and P2P
Push approval status — not necessarily the files themselves — to ERP payment blocks. AP should see compliance status at invoice entry without opening SharePoint.
Measuring centralization success
Track percentage of new vendors with full packet in central system, email exception rate, and average time to find a document during audit requests. Target near-zero audit search time.
Frequently asked questions
- Can we still accept documents by email?
- Only for low-risk exceptions with manual upload by AP into the central system the same day. Default path should be portal upload for audit trail and security.
- How do we handle vendors with multiple entities?
- Separate vendor records and portals per legal entity. Parent company COIs do not substitute for subsidiary W-9s — each entity gets its own document set.
- What about legacy vendors onboarded before centralization?
- Run a migration campaign: request refresh through the portal, attach migrated files with a 'legacy import' tag, and prioritize high-spend vendors first.
- Who validates uploaded documents?
- Route by type: AP for W-9, risk for COI, treasury for banking, legal for contracts. Validation status should display on the vendor record.
Related guides
Put this into a monitored workflow
Vendor Packet handles this continuously — with reminders and an audit trail.