Abstract: The invention relates to a box casing (1), such as a transport box, for shipment and/or storing of goods, which is cost-effective to produce and easy to assemble while at the same time having a considerable strength. The box casing comprises a tray-like bottom member (2) and two wall members (7, 8), each having three interconnected casing walls (9, 10a-b, 13, 14a-b). The wall members are foldable to a position standing in the bottom member and to a substantially flat state to be placed lying on the bottom member, for transferring the box casing between an assembled and a collapsed state. Each wall member comprises corner elements (15) configured to hold the casing walls in place by a resilient function. The invention also relates to a kit for creating such a box casing, as well as use thereof.