Maryland Tax - General Section 10-810

      (a)      A corporation that, during a taxable year, has Maryland taxable income shall file an income tax return.

      (b)      Notwithstanding the provisions of subsection (a) of this section, a corporation which is not otherwise required to file a return shall file a return if the corporation:

            (1)      is not tax exempt under § 10-104 of this title;

            (2)      is required to file a federal income tax return;

            (3)      carries on business within this State; and

            (4)      has income or losses attributable to sources within this State.