Purchase Order Invoice Payments

1. Policy

Issued: September 15, 2014 
Last Reviewed: September 10, 2025 
Last Revised: September 15, 2014 

Applies to:​ Faculty (including part-time, adjunct and visiting faculty), postdoctoral scholars, staff and students (including graduate/undergraduate student workers and graduate assistants) employed by University of Southern California (“USC“ or the “University“) and including those working for the University’s health system (“USC Employees”). This policy continues to apply to individuals who are on sabbatical or other leaves, or who are visiting other institutions. 

2. Policy Purpose

The purpose of this policy is to establish clear guidelines for the submission, verification, and processing of supplier invoices associated with purchase orders.

3. Scope and Application

When the purchase of goods and services is authorized by a purchase order, the supplier must provide an invoice for payment.  This ensures that all invoices are accurately matched with purchase orders and received goods or services before payment is authorized 

4. Definitions

Term Definition 
Purchase Order A formal document issued to a supplier, specifying the details of goods or services to be purchased. It serves as a legally binding agreement that outlines key information such as item descriptions, quantities, prices, delivery dates, and payment term 
Purchase Order Invoice  A billing document issued by a supplier to request payment for goods or services delivered based on a previously issued purchase order (PO). It includes details such as the PO number, item descriptions, quantities, prices, applicable taxes, payment terms, and the total amount due. 

5. Policy Details

Invoice Mailing 

To ensure prompt payment and to avoid late-payment penalties, all invoices should be mailed directly by the supplier to Business Services. Mailing and emailing information can be found on the supplier purchase order. 

The university does not accept supplier statements in lieu of an invoice, except when the statement is for utilities, phone services, or leases. 

Required Invoice Content  

An invoice should at a minimum include all the following information: 

  • “Bill to” USC 
  • “Ship to” USC 
  • Purchase order number 
  • Itemized order details 
  • Amount due 
  • Supplier name 
  • Date of invoice 
  • Remit address of supplier 

The above can be found on the front page of the purchase order 

Tax Review 

All invoices will be assessed according to current tax regulations and handled accordingly. (Refer to: https://sites.usc.edu/procurement/payments/tax-assessment/

Invoice Approvals and Discrepancies 

Department financial approvals are required for invoices related to purchase orders when: 

  • An invoice contains a discrepancy from the purchase order.  A discrepancy is determined at the line level and occurs when the invoice exceeds the purchase order by 20% or $500 (whichever is less) 
  • An invoice is for services for any dollar amount  

Expired Accounts 

An invoice that references an expired account cannot be paid, and an alternative account number (with sufficient funds) must be provided. An invoice that references an expired sponsored project account is routed to Sponsored Project Accounting to review the invoice and determine whether the account can be temporarily reopened to allow payment. Their deliberation is based on whether the goods/services were received within the account’s budget period. If the request is denied, another account must be provided by the department to process payment. 

Overdrawn Purchase Orders/Insufficient Funds 

For an invoice to be processed for payment, the corresponding purchase order must contain sufficient funding 

6. Procedures

Invoice Payments

Tax Assessment

7. Forms

N/A

8. Responsibilities

Position or Office  Responsibilities  
Business Services  Ensure Invoice Payments comply with university policy and local, state and federal laws 

9. Related Information

N/A

10. Contacts

Office Phone 
Business Services  3500 S. Figueroa Street  Suite 210 Los Angeles CA 90089 (213) 740-2716