Mont. Code Ann. § 15-23-103 — Due Date Of Reports And Returns -- Extensions

15-23-103 . Due date of reports and returns -- extensions. (1) Except as provided in subsections (2) and (4), each report or return described in 15-23-301 , 15-23-402 , 15-23-502 , 15-23-701 , or 15-23-517 must be delivered to the department on or before March 31 each year.
(2) Except as provided in subsection (4), each report or return for a natural gas or oil pipeline described in 15-23-301 must be delivered to the department on or before April 15 each year.
(3) Each report described in 15-23-204 , 15-23-212 , 15-23-515 , 15-23-516 , or 15-23-518 must be delivered to the department before April 15 each year.
(4) Beginning January 1, 2024, the reports provided for in subsections (1) and (2) are only required to be delivered to the department in the calendar year the property is valued.
(5) The department may for good cause extend the time for filing a return or report for not more than 30 days.