(1) Every partnership that has Montana source income must file a Form PR-1, Montana Partnership Information and Composite Tax Return, on or before the 15th day of the third month following the close of its annual accounting period.

(2) A six-month extension of time to file a partnership return is automatically allowed if any tax, penalties, and interest due are paid on or before the date the return is filed.

(3) A partnership required to file a Montana partnership information return is subject to a late-filing penalty if:

(a) the Montana partnership information return is not filed by the due date (including extensions);

(b) a copy of the partnership's federal partnership return is not filed with the Montana partnership information return; or

(c) a return is filed that does not include all of the following information:

(i) name, address, and social security or federal identification number of each partner;

(ii) the partnership's Montana source income;

(iii) each partner's distributive share of Montana source income, gain, loss, deduction, or credit or items of income, gain, loss, deduction, or credit; and

(iv) each partner's distributive share of income, gain, loss, deduction, or credit, or item of income, gain, loss, deduction, or credit from all sources.