A filling system on a motor vehicle, having at least two storage tanks for operating materials, comprising a tank closure cover which closes an opening in a body of the motor vehicle and is movable from a first position that closes the opening into a second position that releases the opening, wherein at least two filling openings of the storage tanks are arranged below the tank closure cover, a filler trough that forms an enclosure of the filling opening, wherein the filler trough closes the opening in the body and is fixed to the body; and at least one filler head, wherein the filling openings are formed as a part of the filler head, the filler head defining at least two mouth-hole necks which are combined to form a common component and are integrally connected to each other, each mouth-hole neck forming a filling opening for another storage tank.