Vendor Resources

The university’s standard payment terms are net 30 days unless a payment discount has been established with the vendor. To ensure timely payment refer to invoice requirements and mailing instructions below.

For general questions regarding invoice payment status, please call (314) 935-5750 or contact the appropriate Accounts Payable Coordinator listed below for assistance.

For vendor names beginning with:

Invoice Requirements

The following information must be included on the invoice:

  • A valid Purchase Order (PO) number and corresponding Sold To/Ship To Address of the ordering department.
  • An invoice number, invoice date, invoice detail and amount.
  • A valid Remittance Address to mail check payment. The university’s preferred method of payment to vendors is an electronic payment directly to the vendor’s bank account via an ACH. Additional information about ACH payments is available at the bottom of this page.

Additional requirements

  • Multiple purchase orders may not be combined on a single invoice.
  • Invoices should not include Missouri sales tax. See Paying Sales & Use Tax for additional information and exception certificates.
  • Invoices should be mailed directly to Accounts Payable at the address listed below. Sending invoices to the Sold To / Ship To Address may delay payment.

Mailing Address

Washington University
Accounts Payable
Campus Box 1056
700 Rosedale Avenue
St. Louis, MO 63112-1408


ACH Payment Information

Preferred method of payment to vendors