Folding box made of foldable flat material for meals and/or beverages for catering for passengers on board aircraft or other transport means, comprising - a bottom shell, which comprises a bottom wall and bottom side walls (3 to 6) that protrude from the edges of the bottom wall and are inclined outwards, - a lid shell, which comprises a lid wall and lid side walls (16 to 19) that protrude from the edges of the lid wall and are inclined outwards, - the bottom shell and the lid shell being foldably interconnected, via a fold line on the upper edge of a bottom side wall and on the lower edge of a lid side wall, such that they can be pivoted together out of an open position, in which the bottom wall and the lid wall are arranged in a common plane, into a closed position, in which the bottom shell and the lid shell enclose an inner space (35.1, 36.1), and - first locking elements (14, 13.21, 13.22) on the bottom shell and second locking elements (27, 26.1, 26.2) on the lid shell, the first locking elements being able to interlock with the second locking elements in the closed position of the bottom shell and the lid shell, characterised by - an insertion tab protruding from the upper edge of a bottom side wall and an additional punched-out portion in the opposing bottom side wall, such that in the closed position of the bottom shell and the lid shell, the insertion tab can be inserted into the additional punched-out portion of an additional folding box that is identical, and/or - an additional insertion tab on the lower edge of the lid side wall and a punched-out portion in an opposing lid side wall, such that in the closed position of the bottom shell and the lid shell, the additional insertion tab can be inserted into the punched-out portion of an additional folding box that is identical. - a bottom shell, which comprises a bottom wall and bottom side walls (3 to 6) that protrude from the edges of the bottom wall and are inclined outwards, - a lid shell, which comprises a lid wall and lid side walls (16 to 19) that protrude from the edges of the lid wall and are inclined outwards, - the bottom shell and the lid shell being foldably interconnected, via a fold line on the upper edge of a bottom side wall and on the lower edge of a lid side wall, such that they can be pivoted together out of an open position, in which the bottom wall and the lid wall are arranged in a common plane, into a closed position, in which the bottom shell and the lid shell enclose an inner space (35.1, 36.1), and - first locking elements (14, 13.21, 13.22) on the bottom shell and second locking elements (27, 26.1, 26.2) on the lid shell, the first locking elements being able to interlock with the second locking elements in the closed position of the bottom shell and the lid shell, - an insertion tab protruding from the upper edge of a bottom side wall and an additional punched-out portion in the opposing bottom side wall, such that in the closed position of the bottom shell and the lid shell, the insertion tab can be inserted into the additional punched-out portion of an additional folding box that is identical, and/or - an additional insertion tab on the lower edge of the lid side wall and a punched-out portion in an opposing lid side wall, such that in the closed position of the bottom shell and the lid shell, the additional insertion tab can be inserted into the punched-out portion of an additional folding box that is identical.