(1) Every S corporation that has Montana source income must file an Annual Montana S Corporation Information Return, Form CLT4-S, on or before the 15th day of the third month following the close of its annual accounting period.

(2) See ARM 42.15.201 and 42.15.202 to determine the time for filing a short-period return.

(3) For tax years beginning before January 1, 2003, the S corporation must file a Pass-through Entity Extension Form PT-EXT to extend the filing date. For tax years beginning after December 31, 2002, a pproval of an extension to file the S corporation's federal income tax return for an S corporation automatically extends the time for filing the Montana return to the date approved for filing the federal return.

(4) An S corporation required to file a Montana S corporation information return is subject to a late filing penalty if:

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

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

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

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

(ii) the S corporation's Montana source income;

(iii) each shareholder's pro rata share of separately and non-separately stated Montana source income, gain, loss, deduction, or credit, or item of income, gain, loss, deduction, or credit; and

(iv) each shareholder's pro rata share of separately and non-separately stated income, gain, loss, deduction, or credit, or item of income, gain, loss, deduction, or credit from all sources.