A shell corporation is an entity with no significant assets or business operations. There are a number of reasons for having a shell corporation, including the following:
It has just been formed and is being used for the collection of financing before acquiring assets and starting operations.
It was an active public company at one time, and has been pared down for later use as a public shell company to take another business public.
It is being used as a vehicle for tax avoidance.
It is being used to engage in financial activities in other countries.
It has been created as a ploy by a fraudulent operator, who uses it as a front to attract funds and other payments from third parties.