Voyager normally permits users to specify that a prepay be held for charges associated with a particular charge code. (See “To automatically apply the prepay to charges to a particular charge code”.) If you want to turn off this feature, so that prepays are always applied only to the prepay charge code, activate the Voyager Prepayment Charge Code on Receipt optional parameter. With this option activated, users cannot specify a different charge code for prepays on the Receipt screen.