In an accounting machine having an alphanumeric printing mechanism and a numeric printing mechanism the paper carriage for the alphanumeric mechanism is guided by a rail located to the rear of the numeric mechanism. This latter is adapted to print on a tally roll adapted to be housed in a substantially semicylindrical plate located under the guiding rail and provided with a set of parallel apertures for a set of rotatable rollers supporting the tally roll. The paper of the roll is so guided as to pass after printing along a path beneath said guide rail, a slit on the rear wall of said cover being provided for the exit of the printed paper of said roll.