143.351.  Fiduciary adjustment. — 1.  An adjustment shall be made in determining the Missouri taxable income of a resident estate or trust under section 143.341, or the Missouri adjusted gross income of a resident beneficiary of any estate or trust under section 143.121, subsection 4, in the amount of the share of each in the Missouri fiduciary adjustment as determined in this section.

  2.  The Missouri fiduciary adjustment shall be the net amount of the modifications described in subsections 2, 3, and 4 of section 143.121 (if the estate or trust is a beneficiary of another estate or trust), subsection 5 of section 143.121, section 143.141, and section 143.171.  The net amount of such modification shall not include any modification to the extent such items are not determinants of the federal distributable net income of the estate or trust.

  3.  (1)  The respective shares of an estate or trust and its beneficiaries (including, solely for the purpose of this allocation, nonresident and charitable beneficiaries) in the fiduciary adjustment shall be in proportion to their respective shares of the sum of federal distributable net income of the estate or trust and the amount paid or required to be paid to a charitable organization to the extent such amount is attributable to income for the current year.

  (2)  If the estate or trust has no federal distributable net income for the taxable year, the share of each beneficiary in the fiduciary adjustment shall be in proportion to his share of the estate or trust income for such year, under the applicable law or the government instrument, which is required to be distributed currently and any other amounts of such income distributed in such year.  Any balance of the fiduciary adjustment shall be allocated to the estate or trust.

  (3)  The director of revenue may, by regulation, establish such other method or methods of determining to whom the items comprising the fiduciary adjustment shall be attributed, as may be appropriate and equitable.  Such method may be used by the fiduciary in his discretion whenever the allocation of the fiduciary adjustment, pursuant to subdivision (1) or (2) of this subsection would result in an inequity which is substantial both in amount and in relation to the amount of the fiduciary adjustment.