Mont. Code Ann. § 15-70-417 — Penalties For Delinquency

15-70-417 . Penalties for delinquency. (1) Except for tax due under the agreement adopted under 15-70-121 , any fuel tax not paid within the time provided in 15-70-113 (3) and 15-70-410 is delinquent. A penalty of 10% must be added to the tax, and the tax bears interest at the rate of 1% per month, prorated daily, from the date of delinquency until paid.
(2) Except as provided in subsection (3), a statement filed after the date required in 15-70-410 is subject to a $100 penalty.
(3) (a) The department shall waive the penalty if the late filing is the first offense within a 3-year period of timely filings.
(b) The department may waive the penalty if the director or the director's designee determines the late filing or payment to be beyond the distributor's control.
(4) If a distributor or other person required to pay the tax willfully fails, neglects, or refuses to file any statement required by this part or willfully fails to pay the tax within the time provided, the department may revoke any license issued under this part.
(5) Except as provided in subsection (3), the department shall proceed to collect a delinquent tax, with penalties and interest. At the request of the department, the attorney general shall commence and prosecute to final determination in any court of competent jurisdiction an action to collect the tax.