Mont. Code Ann. § 15-65-113 — Audits -- Records

15-65-113 . Audits -- records. (1) The department of revenue may audit the books and records of any seller to ensure that the proper amount of tax imposed by 15-65-111 has been collected. An audit may be done on the premises of the seller or at any other convenient location.
(2) The department may request the seller to provide the department with books, ledgers, registers, or other documents necessary to verify the correct amount of tax.
(3) The seller shall maintain and have available for inspection by the department books, ledgers, registers, or other documents showing the sales price and tax collections for the preceding 5 years.
(4) Except in the case of a person who, with intent to evade the tax, purposely or knowingly files a false or fraudulent return violating the provisions of this part, the amount of tax due under any return must be determined by the department within 5 years after the return is made, and the department thereafter is barred from revising any return or recomputing the tax due after the department has determined the tax, and no proceeding in court for the collection of the tax may be instituted unless notice of any additional tax is provided within the period.
(5) An application for revision may be filed with the department by a seller within 5 years from the original due date of the return.