Abstract: The following relates generally to determining an optimal rewards program (e.g., of a credit card or debit card), and purchasing one or more items via the optimal rewards program. In some embodiments, a cardholder initiates a first user-initiated interaction between a bank card and a bank card machine, which generates a first purchase authorization request. One or more processors of a first bank then determine an optimal rewards program for the purchase, and then decline the first purchase authorization request. The cardholder may then initiate a second user-initiated interaction between the bank card and the bank card machine, which generates a second purchase authorization request. One or more processors of a second bank (e.g., a bank of the rewards program) may then authorize the second purchase authorization request. Alternatively, some embodiments complete a purchase according to a determined optimal rewards program with only one user-initiated interaction.