Mont. Code Ann. § 15-31-111 — Return To Be Filed -- Penalty And Interest

15-31-111 . Return to be filed -- penalty and interest. (1) A corporation subject to the corporate income tax imposed under this chapter shall for each tax period file an accurate return of its net income for the tax period in the manner and form prescribed by the department. The return must contain all of the information that is appropriate and in the opinion of the department necessary to determine the correctness of the net income disclosed by the return and to carry out the provisions of this chapter. The return must be signed by the president, the vice president, the treasurer, the assistant treasurer, or the chief accounting officer.
(2) (a) Except as provided in subsection (2)(b), if the corporation is reporting on a calendar year basis, the return must be filed with the department on or before May 15 following the close of the calendar year. If the corporation is reporting on a fiscal year basis, the return must be filed with the department on or before the 15th day of the 5th month following the close of its fiscal year.
(b) (i) If the due date of the return falls on a holiday that defers a filing date as recognized by the internal revenue service and that is not observed in Montana, the return may be made on the first business day after the holiday.
(ii) The department may extend filing dates and defer or waive interest, penalties, and other effects of late filing for a period not exceeding 1 year for taxpayers affected by a federally declared disaster or a terroristic or military action recognized for federal tax purposes under 26 U.S.C. 7508A.
(3) (a) A corporation is allowed an automatic extension of time for filing its return of up to 6 months following the date prescribed for filing of its tax return. The tax, penalty, and interest must be paid when the return is filed. Penalty and interest must be added to the tax due as provided in 15-31-510 (2).
(b) The department may grant an additional extension of time for the filing of a return whenever in its judgment good cause exists.
(4) Receivers, trustees in bankruptcy, or assignees operating the property or business of a corporation subject to the corporate income tax imposed by this chapter shall make the return in the same manner and form as the corporation is required to make the return. Any corporate income tax due on the basis of the return is assessed and collected in the same manner as if assessed directly against the corporation of whose business or property the receiver, trustee, or assignee has custody and control. The receiver, trustee, or assignee shall pay the tax out of the property of the corporation, prior to the claims of creditors or stockholders.