Form W-9 is used to collect Taxpayer Identification Numbers (TINs) and other key information from U.S.-based vendors, contractors, freelancers, and other nonemployees. It helps businesses ensure accurate tax reporting and avoid IRS penalties.

Businesses should collect a completed Form W-9 before paying a vendor or contractor. This applies to any U.S. nonemployee vendor that may be subject to 1099 reporting. Best practice is to collect W-9s during vendor onboarding — not after a payment is made.

Yes. Avalara 1099 & W-9 allows businesses to digitally request, collect, and store W-9 forms in a secure, compliant platform. You can validate TINs in real time to help reduce IRS B-notices and avoid backup withholding.