Iowa Code § 12.21: Accepting credit card payments.

The treasurer of state may enter into an agreement with a financial institution to provide credit card receipt processing for state departments which are authorized by the treasurer of state to accept payment by credit card. A department which accepts credit card payments may adjust its fees to reflect the cost of processing as determined by the treasurer of state. A fee may be charged by a department for using the credit card payment method notwithstanding any other provision of the Code setting specific fees. The treasurer of state shall adopt rules to implement this section.