A loan system program comprises a loan account having a loan principal on a purchased item, and a secondary account used to pay the amortized interest on the loan principal. A user deposits, such as through automatic deposit, user payments directly into the loan account, thus paying down the loan principal. The user then uses the secondary account for personal expenses that would otherwise be met by the deposited user payments. At the end of the month or grace period, the user pays off the monthly interest on the loan account with the secondary account. The lender than raises the loan balance of the loan account to cover the secondary account balance. At least a portion of the next user deposit to the loan account covers the raise loan balance, and another portion is used to pay down the loan principal.