This invention has as its object to allow a print system having a middle insert print function to insert an index sheet without billing for it. According to a preferred embodiment, when it is set to insert an index sheet, a print application (305) executes a non-billing command transmission preparation process (step S603). Upon completion of the preparation process, the print application transmits a non-billing command to a printer (step S604). The print application then executes an index sheet output process (step S606). The printer excludes the index sheet from sheets to be billed in accordance with the received non-billing command.