In an embodiment, a mobile storage system has a mobile container with an automated storage and retrieval system arranged inside. The automated storage and retrieval system has a storage grid structure having vertical members defining multiple columns, such as storage columns for storing storage bins on top of each other in vertical stacks. The vertical members are interconnected at their upper ends by a first rail system arranged to guide at least one bin handling vehicle thereon. The bin handling vehicle is configured to raise storage bins from, and lower storage bins into, the storage columns, and to transport the storage bins above the storage columns. The invention also relates to a method for providing such a system. The invention also relates to a mobile storage system having a connected plurality of mobile containers and a method for providing such a system.