(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) Corporations that are members of a unitary group filing a single return must use intrastate apportionment to calculate the net operating loss and net operating loss deduction for each member of the unitary group that is engaged in business in the state. A net operating loss for one member of a unitary group cannot be carried back or carried over to offset the income of another member included in the unitary group.
(a) Each member of a unitary group engaged in business in this state must calculate its individual share of the unitary group's net operating loss by applying its individual apportionment factor to the net operating loss of the unitary group.
(b) For purposes of calculating the net operating loss deduction, each member of a unitary group engaged in business in this state must calculate its individual share of the unitary group's net income by applying its individual apportionment factor to the net income of the unitary group, then applying its individual net operating loss available as calculated in (a).
(3) 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.
(4) 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.