for which companies internal audit will apply

in only certain cases law makes compulsory for intenal audit  like for listed companies it is mandatory and those concern which satisfies average turn over and paid up capital ceilings.otherwise it is companies wish if it is large concern she can employ I.A for maintenance of internal control and for making necessary suggestions for improvement of effectiveness and efficency.for details  conditionsrefer AAS-7 "relying upon the work of I.A".