In a multiple application card system including an IC card comprising a microprocessor, a read-only memory, a random access memory and an electronically erasable programmable read only memory, a system for controlling access to one or more sets of programming instructions embedded in said read-only memory comprising means for storing on said IC card for at least one application loaded onto said card at least one access flag having a value indicating whether or not access by the at least one application to the at least one set of programming instructions shall be granted and means dependent on said value for allowing access to one or more sets of programming instructions.