Iowa Code
Chapter 536C - LENDER CREDIT CARDS
Section 536C.7 - Books and records.

536C.7 Books and records.
A person who issues credit cards shall keep such books, accounts, and records as will enable the administrator to determine whether or not the person is complying with the provisions of this chapter and chapter 537. The person shall not be required to preserve or keep their records or files for a longer period than three years following the date of the final payment.
91 Acts, ch 216, ยง21