Carnegie Mellon University

Yes. Fees are assessed by the credit card networks and vary based on several factors, such as card brands, type of debit or credit card (reward levels), and online versus card present sales.

The university passes these fees on to the campus merchants and does not charge additional fees to merchants who choose to accept credit cards.

No. The use of American Express disallows the university from charging a convenience fee. 

The university ecommerce credit card system is Cashnet. Use of any other credit card process is strongly discouraged.  Exceptions must be approved on a case-by-case basis.