The Constitution and List I in the seventh schedule says that tax on income is imposed by the Union government. The Constitution concedes exempt to state governments from charging income tax, also, state’s property and income is exempted from union taxation.
The exemption provided is for government as well as non-government activities of a state. But, state-owned companies or corporations claimed that their trade or business is carried on behalf of the state government and in reality, it is the state government which carries on business through them. The surplus generated by such activities belongs to the state government. Hence, they are entitled to be treated as state.