Providing change to gaming machine players is facilitated by the use of a change card having a memory storing a cash value which a change person can use to input a credit into a gaming machine in exchange for cash from a player. A game monitor unit having a card reader, a keypad and a display is attached to the gaming machine and can be used to authorize and transfer a selected cash value to the credit meter of the gaming machine from the change card. Cash values along with authorizations and security codes are input to the change card at a change station utilizing a similar monitor unit. Financial controls and security can be enhanced by transmitting data relating to change card transactions from the gaming machine and the change system to a central data system.