Abstract: In a folding apparatus with a transverse cutting and transverse folding unit fed by a first longitudinal folding unit and with a second longitudinal folding unit followed by a delivery unit, simple development and expansion of the folding apparatus step by step is made possible by arranging the transverse cutting and transverse folding unit on a basic frame and arranging the second longitudinal folding unit on a lower additional frame. Furthermore the basic and additional frame are arranged at the same level and are provided with connection structure adjacent to each other and over the connection on the basic frame there is a further connection structure for a superposed frame with transverse and longitudinal forming unit. The additional frame is provided with support surfaces for the superposed frame which has corresponding surfaces.