A data communication apparatus has a transmission function of transmitting data to a pre-set transmission destination. A data communication apparatus, when importing at least one of an address book and setting information based on import data including data that has been exported by another data communication apparatus, determines data to be imported. The data communication apparatus determines, with respect to each of the address book and the setting information, if the address book or the setting information is actually to be imported. Furthermore, if it is determined that either one of the address book and the setting information is to be imported, but the other one is not to be imported, the use of the transmission function is restricted after import processing has been performed based on the import data.