Chasing a W-9 in December for a vendor you paid in March is a self-inflicted wound. Collect everything once, before the first check goes out.
The checklist
- W-9 with a TIN that matches the legal name
- Certificate of insurance with your job named as additional insured
- License number, verified against the state board
- Banking details captured through a secure form — never email
- Default cost codes so their invoices code themselves
Make it the vendor's job
Send one onboarding link; the vendor uploads their own documents before they can submit a bill. Expirations (COIs especially) get flagged automatically, and your pay packages never stall on missing paperwork.
