By using an external portable recording medium that stores a personal ID, a communications apparatus automatically transmits the personal ID and its own terminal identification information to a center apparatus. The center apparatus manages the personal ID and the terminal identification information so that they are correlated with each other. For example, the terminal identification information includes a called-party address, a communication mode, and a position ID Further, the center apparatus manages a present/absent mode for each personal ID. During the present mode, the center apparatus forwards a call using a personal telecommunication number, such as a UPT (universal personal telecommunication) number, which corresponds to a certain personal ID to a communications apparatus that corresponds to the personal ID. During the absent mode, the center apparatus automatically records a message. Further, the communications apparatus reads a card ID, which may be composed of a personal ID, a personal telecommunication number, etc., from the IC card, and compares it with a card ID that is stored in a card ID storing section. If they are identical, the communications apparatus judges that the IC card is not a new one and skips a center authentication operation. If they are not identical, the communications apparatus judges that the IC card is a new one and effects the center authentication operation.