PSC Procedural Statement: W-9/W-8 & Vendor (Supplier) Authorization

Effective Date: February 26, 2016


This PSC Procedural Statement sets forth university requirements for supplier (vendor) registration prior to the issuance of a purchase order or payment.

Procedural Statement

The Procurement Service Center (PSC) requires that external suppliers (vendors) register through the CU Supplier Portal in order for the University to buy or pay for goods or services from the supplier. Periodically, the PSC may require an updated registration, for example, to ensure correct reporting of Tax Identification Number (TIN)/name combinations and to provide evidence that a payee is a valid individual or business (thus minimizing the risk of making inappropriate payments to fraudulent entities); and/or to ensure accurate reporting of business classifications.

The Supplier Portal registration process replaces the submission of paper W-9 and W-8 forms to the PSC.


  • Study subject payments. Study subjects submit the paper W-9 (IRS form) instead of registering through the Supplier Portal. The study subject's W-9 form must accompany the Study Subject Payment (SSP) form to ensure that the individual is correctly set up under the Clinical Trial supplier record.
  • Reimbursements/refunds. Tax documents are not needed in order to issue reimbursements using the Non-Employee Reimbursement (NR) form … or to process refunds using the Payment Authorization (PA) form. Therefore, recipients of reimbursements or refunds do not need to register through the Supplier Portal or submit W-9 forms.
  • Stipends, awards, and grants on the Payment Authorization (PA) form. The payee's paper W-9 (IRS form) must accompany the PA form to ensure that the individual is correctly set up.
  • CU employees/students. CU employees and CU students are not considered to be external suppliers. (Furthermore, employee/student TIN information is already on file.)

Related Information

Related Administrative Policy Statements (APS), Other Policies and Procedures