In 1956, the government of the Federal Republic of Germany changed the regulations for motor vehicles. Class IV licences issued from that time onward could only be used to operate small motorcycles and could no longer be used to operate motor vehicles with a capacity of less than 250 cc. At the same time, the maximum capacity allowed for the Isetta's tax category was 300 cc. Class IV licences issued before the change in the regulations were grandfathered and allowed to be used as before.