1. If a person's federal taxable income or federal income tax liability for any taxable year is changed or corrected by the United States internal revenue service, or other

competent authority, the person shall report the changes or corrections within ninety days after the date of the final determination of them by filing an amended state income tax return or other information as required by the tax commissioner.

2. Notwithstanding the provisions of subsection 1, if a person files an amended federal income tax return for any taxable year, the person shall file an amended state income tax return and a copy of the amended federal income tax return within ninety days after the amended federal income tax return is filed.