A method and device for transmitting communications on a bus system, as well as a bus system, is provided, in which the communications are transmitted in communication frames and the communication frames and the communications contain a security sequence. In the bus system, communications of various lengths can be transmitted, and for all of the communications to be transmitted in the bus system, a maximum length of a communication is provided. A first code is contained in the communication frame, by means of which the maximum length of the respective communication to be transmitted can be specified.