§ 621. Credits to trust beneficiary receiving accumulation distribution. (a) General. A resident beneficiary of a trust whose New York adjusted gross income includes all or part of an accumulation distribution by such trust, as defined in section six hundred sixty-five of the internal revenue code, including a beneficiary who is required to make the modification required by paragraph forty of subsection (b) of section six hundred twelve of this part, shall be allowed (1) a credit against the tax otherwise due under this article for all or a proportionate part of any tax paid by the trust under this article or under former article sixteen of this chapter (as such article was in effect on or before December thirtieth, nineteen hundred sixty), for any preceding taxable year which would not have been payable if the trust had in fact made distributions to its beneficiaries at the times and in the amounts specified in section six hundred sixty-six of the internal revenue code; and (2) a credit against the taxes imposed by this article for the taxable year for any income tax imposed on the trust for the taxable year or any prior taxable year by another state of the United States, a political subdivision thereof, or the District of Columbia, upon income both derived therefrom and subject to tax under this article, provided that the amount of the credit shall not exceed the percentage of the tax otherwise due under this article determined by dividing the portion of the income that is both taxable to the trust in such other jurisdiction and taxable to the beneficiary under this article by the total amount of the beneficiary's New York income.

(b) Limitation. The credits under this section shall not reduce the tax otherwise due from the beneficiary under this article to an amount less than would have been due if the accumulation distribution or his part thereof were excluded from his New York adjusted gross income.