a billing data is relieved by a relief method of billing data when a failure occurs on svc calls which subscribers connect and disconnect . the relief method of billing data on an asynchronous transfer mode switching system includes an asynchronous transfer mode switch , a terminator provided on an input side of said asynchronous transfer mode switch for counting the number of cells sent from subscribers or other switching system , and a call controller for controlling paths on said asynchronous transfer mode switch , collecting a count value of the numbers of cells on said terminator , and creating billing data according to the count value of the collected cell number and call control data , wherein only the count value of the number of the cells counted on said terminator is removed from the values to be initialized on initialization caused by a failure .