Around the UK councils vary on their regulations surrounding the need for planning permission for individuals and businesses using shipping containers for storage. Similarly, shipping containers may be converted into offices, canteens, cafés, toilet blocks, changing rooms, and more, and you should always liaise with the land owner and your local council to obtain any necessary permissions prior to investing into a standard or converted shipping container.
Technically speaking, shipping containers are moveable structures, however, as they are being used more and more for static storage and conversion, they are becoming increasingly more permanent for individuals and businesses.
Whether or not planning permission is required for your shipping container also depends on the environment in which the container is sited. Containers located in and around green belt or on a drive way on a housing estate are more likely to require planning permission to those located on private farm land or business premises.
A quick call to your local planning office will put your mind at rest as to whether or not it is advised that you have planning permission for your shipping container.