1. “Gross income” includes all gains, profits, earnings and other income of the taxpayer from whatever sources derived during the income period, including but not limited to interest from obligations issued by the United States government or any political subdivision or any instrumentality thereof, or any state or political subdivision thereof, or issued by any foreign country or nation or political subdivision thereof; all rents, compensation for services, commissions, brokerage and other fees; all gains or profits from the sale or other disposition of any property, real or personal, tangible or intangible; and all recoveries on losses sustained in the ordinary course of business subsequent to July 1, 1946; provided, however, that recoveries on such losses sustained during any prior income period within which the deductions, as permitted by subsection 3 of this section, exceeded the taxpayer’s gross income for such income period, computed in accordance with this subsection, shall not be included in the taxpayer’s gross income for the income period in which they were received to the extent of such excess. Dividends received on shares of stock of any banking institution liable to a tax under this law shall not be included in gross income.

2. “Net income” means gross income as defined in subsection 1 of this section minus the deductions allowed in subsection 3 of this section, and adjusted to the extent provided in section 148.097.

3. In computing net income there shall be allowed as deductions all ordinary and necessary expenses paid or incurred by the taxpayer during the income period in carrying on its trade or business. Without limiting the generality of the foregoing, there shall be allowed as deductions a reasonable allowance for salaries and other compensation for personal services actually rendered; rents, repairs, and bad debts and debts ordered to be charged off by the director of finance or the comptroller of the currency or their respective examiners as the case may be; interest; cost of insurance and advertising; all taxes paid or accrued during the income period to the United States and all taxes paid or accrued on real estate or tangible personal property owned by the taxpayer and held for lease or rental to others, to the state of Missouri or any political subdivision thereof; all contributions paid or accrued pursuant to the unemployment compensation law of Missouri; reasonable allowances for depreciation and depletion; amortization of premiums on bonds, debentures, notes or other securities or evidences of indebtedness; a reasonable allowance for payments or contributions to or on account of any pension or retirement fund or plan for its officers or employees; contributions to any corporation, association or fund organized and operated exclusively for religious, charitable, scientific, literary or educational purposes, no part of the net earnings of which inure to the benefit of any private shareholder or individual to an amount which does not exceed five percent of the taxpayer’s net income as computed without the benefit of this deduction; losses from the sale or disposition of any property, real or personal, tangible or intangible; and all other losses sustained during the income period not compensated for by insurance.

4. Net income shall be computed in accordance with the method of accounting regularly employed in keeping the books of the taxpayer, unless such method does not clearly reflect the income, in which case the computation shall be made in accordance with such method as in the opinion of the director does clearly reflect the income.