26 CFR § 1.581-2 - Mutual savings banks, building and loan associations, and cooperative banks.
(a) While the general principles for determining the taxable income of a corporation are applicable to a mutual savings bank, a building and loan association, and a cooperative bank not having capital stock represented by shares, there are certain exceptions and special rules governing the computation in the case of such institutions. See section 593 for special rules concerning reserves for bad debts. See section 591 and § 1.591-1, relating to dividends paid by banking corporations, for special rules concerning deductions for amounts paid to, or credited to the accounts of, depositors or holders of withdrawable accounts as dividends. See also section 594 and § 1.594-1 for special rules governing the taxation of a mutual savings bank conducting a life insurance business.
(b) For the purpose of computing the net operating loss deduction provided in section 172, any taxable year for which a mutual savings bank, building and loan association, or a cooperative bank not having capital stock represented by shares was exempt from tax shall be disregarded. Thus, no net operating loss carryover shall be allowed from a taxable year beginning before January 1, 1952, and, in the case of any taxable year beginning after December 31, 1951, the amount of the net operating loss carryback or carryover from such year shall not be reduced by reference to the income of any taxable year beginning before January 1, 1952.