There are provided a data communication apparatus and a transmission reservation managing method that are capable of collectively managing transmissions of the same or common data by a plurality of transmission methods. A plurality of destinations for the same data input by the input means are designated. The plurality of destinations being destinations to which data are to be transmitted by respective different transmission methods. the same data are transmitted to the designatd destinations by the respective different transmission methods. Information related to transmission by the data communication apparatus are managed by associating a predetermined identifier with each of the input data.