A communication apparatus that avoids a situation in which all sessions are occupied by fax transmission. The communication apparatus is capable of conducting fax communications via an IP network using a plurality of sessions. An acquisition unit acquires a receive session count which indicates the number of sessions set to be used exclusively for fax reception when the plurality of sessions include any unoccupied session which is a session available for fax communications. A transmission starting unit determines whether or not sessions corresponding in number to the receive session count acquired by the acquisition unit are able to be secured as the receive sessions, and start fax transmission using the unoccupied session if the sessions are able to be secured.