Forms for non-Maryland businesses. Every other corporation that is subject to Maryland income tax law and has income or losses attributable to sources within Maryland must also file Form 500.You have two options: download and complete a paper form, or apply online. Maryland permits a subsidiary corporation to have only one director, who may be a citizen or resident of another state or nation. Foreign qualification is the process of registering to do business in a state other than the one in which you incorporated. To withdraw or cancel your foreign LLC from Maryland, file a Certificate of Cancellation of a Foreign Limited Liability Company Registration with the SDAT. After completing the Maryland return, assemble your return in the following order: Form 500, any required Maryland forms and their related attachments, any. The. Maryland filing will not be complete unless the required federal copy is attached. All foreign corporations must register with Maryland to legally conduct business. The foreign corporation receives amounts under a contract for personal services of an individual whom the corporation has no right to designate (i.e.