A right-angled parallelepipedic box casing for shipment and/or storing of goods, comprising: - a bottom member having a rectangular loading surface configured to form a bottom of the box casing in an assembled state thereof and further provided with a frame structure enclosing the loading surface on each side thereof by vertical front, rear, and first and second lateral frame walls at front, rear, and first and second lateral edges of the bottom member, respectively, so as to provide the bottom member with a tray-like shape, - a first wall member comprising a rear casing wall configured to rest by a lower end on the loading surface on the inside of the rear frame wall and extend therealong in the assembled state of the box casing, and first and second lateral casing walls hingedly connected at a rear end (11a-b) to first and second outer ends of the rear casing wall, respectively, so as to be configured to rest by a lower end on the loading surface on the inside of the first and second lateral frame wall, respectively, and extend therealong in the assembled state of the box casing, said first and second lateral casing walls of the first wall member being foldable to a position overlapping the rear casing wall in a collapsed state of the box casing, - a second wall member comprising a front casing wall configured to rest by a lower end on the loading surface on the inside of the front frame wall and extend therealong in the assembled state of the box casing, and first and second lateral casing walls hingedly connected at a front end to first and second outer ends of the front casing wall, respectively, so as to be configured to rest by a lower end on the loading surface on the inside of the first and second lateral frame wall, respectively, and extend therealong overlapping the first and second lateral casing walls of the first wall member in the assembled state of the box casing, said first and second lateral casing walls of the second wall member being foldable to a position overlapping the front casing wall in a collapsed state of the box casing, characterized in that each of the first and second wall members further comprises, for each inner corner of the box casing in the assembled state defined by two adjacent casing walls (9, 10a-b, 13, 14a-b) of the same wall member (7, 8), a corner element having two stiff plate-like parts (16a-b) hingedly interconnected by a flexible portion, each plate-like part (16a-b) being in the assembled state of the box casing configured to be arranged internally of a separate one of two adjacent casing walls (9, 10a-b, 13, 14a-b) while extending along the corner from a bottom region to a top region of the wall (9, 10a-b, 13, 14a-b), and wherein the corner elements are configured to through said flexible portions thereof store potential energy urging the plate-like parts (16a-b) away from each other and thereby the lateral casing walls (10a-b, 14a-b) against the frame walls (6a-b) of the bottom member in the assembled state of the box casing. - a bottom member having a rectangular loading surface configured to form a bottom of the box casing in an assembled state thereof and further provided with a frame structure enclosing the loading surface on each side thereof by vertical front, rear, and first and second lateral frame walls at front, rear, and first and second lateral edges of the bottom member, respectively, so as to provide the bottom member with a tray-like shape, - a first wall member comprising a rear casing wall configured to rest by a lower end on the loading surface on the inside of the rear frame wall and extend therealong in the assembled state of the box casing, and first and second lateral casing walls hingedly connected at a rear end (11a-b) to first and second outer ends of the rear casing wall, respectively, so as to be configured to rest by a lower end on the loading surface on the inside of the first and second lateral frame wall, respectively, and extend therealong in the assembled state of the box casing, said first and second lateral casing walls of the first wall member being foldable to a position overlapping the rear casing wall in a collapsed state of the box casing, - a second wall member comprising a front casing wall configured to rest by a lower end on the loading surface on the inside of the front frame wall and extend therealong in the assembled state of the box casing, and first and second lateral casing walls hingedly connected at a front end to first and second outer ends of the front casing wall, respectively, so as to be configured to rest by a lower end on the loading surface on the inside of the first and second lateral frame wall, respectively, and extend therealong overlapping the first and second lateral casing walls of the first wall member in the assembled state of the box casing, said first and second lateral casing walls of the second wall member being foldable to a position overlapping the front casing wall in a collapsed state of the box casing,