There is provided a technique of, in a communication apparatus capable of executing facsimile communication by a deemed voice scheme, enabling generation of a communication error to be prevented regardless of a voice encoding scheme used to encode a facsimile signal. To achieve this, a communication apparatus (first FAX apparatus) establishes a voice signal transmission session with the second FAX apparatus serving as a partner apparatus in FAX communication for FAX communication by the deemed voice scheme. The first FAX apparatus determines a voice encoding scheme which is used in the established session to encode a FAX signal into a voice signal. In accordance with the determination result, the first FAX apparatus limits modulation schemes usable in generation of the FAX signal when performing FAX communication by the deemed voice scheme.