An information processing apparatus stores a plurality of item codes in a storage unit, each of which is associated with an item type. The apparatus accepts a new order, which includes an item code and a user ID, from a customer terminal. The apparatus then searches for an item type stored in the storage unit based on the item code included in the new order, and checks whether or not the new order is a duplicate based on the item code and the user ID included in the new order. The apparatus notifies the customer terminal of the checking result, where check is controlled so as to check or not to check a new order based on the item type associated with the order.