(1) Every corporation claiming a net operating loss deduction for any taxable period must file with its return for such period a schedule showing in detail the computation of the net operating loss deduction claimed.

(2) If a corporation has a net operating loss which when carried back to a prior taxable period results in an overpayment of tax for such taxable period, a refund may be obtained by filing an amended return for that period claiming the net accordingly. Interest does not accrue on overpayments of tax resulting from a net operating loss carryback or carryover.

(a) For tax periods beginning after March 13, 1997, claims for refund of tax resulting from a net operating loss carryback must be filed in accordance with 15-31-509 , MCA.

(b) For tax periods beginning before March 13, 1997, claims for refund of tax resulting from a net operating loss carryback must be filed within five years from the due date of the return for the year to which the loss is carried or within one year from the date of the overpayment, whichever period expires later.

(3) Any net operating loss carried over to any taxable years beginning after December 31, 1978, must be calculated under the provisions of 15-31-114 , MCA, and the rules promulgated thereunder that are effective for the taxable year for which the return claiming the net operating loss carryover is filed.