A data transmitting/receiving method for charging the reception of pay data in units of a reception or in units of a group to which receivers belong with a high degree of freedom and its receiver. The transmission side allocates the same group identification number (IRD_Gr_ID) to receivers which receive data from the transmission side under a reception contract, have different individual identification numbers (IRD_ID), and belong to the same group, and manages the reception contract by means of the individual identification number (IRD_ID) and the group identification number (IRD_Gr_ID).