Mo. Rev. Stat. § 469.459: Taxes to be paid from income or principal, when.

1. A tax required to be paid by a trustee based on receipts allocated to income shall be paid from income.

2. A tax required to be paid by a trustee based on receipts allocated to principal shall be paid from principal, even if the tax is called an income tax by the taxing authority.

3. A tax required to be paid by a trustee on the trust's share of an entity's taxable income shall be paid:

(1) From income to the extent that receipts from the entity are allocated to income; and

(2) From principal to the extent that receipts from the entity are allocated only to principal.

4. After applying subsections 1 to 3 of this section, the trustee shall adjust income or principal receipts to the extent that the trust's taxes are reduced because the trust receives a deduction for payment made to a beneficiary.