A capless closure assembly for a fuel tank filler tube has a housing adapted for covering a bulkhead with an opening disposed on a proximal end of the filler tube, a sliding element disposed in the housing, and a door that is biased to close an aperture in the housing. The sliding element is movable between a first position that exposes the opening in the bulkhead and a second position that covers the opening in the bulkhead, and the door cooperates with the sliding element to move the sliding element from the second position to the first position as the door is opened.