N.Y. Comp. Codes R. & Regs. tit. 20, § 3-6.3
(a) The term subsidiary capital means the total of:
(d) Indebtedness on which any interest is deducted by the subsidiary in computing any New York State franchise tax imposed on the subsidiary under either article 9-A, 32 or 33 of the Tax Law may not be included in the taxpayer's subsidiary capital. Such indebtedness is includible in investment capital if it meets the definition of investment capital as set forth in section 3-3.2 of this Part. Otherwise, it constitutes business capital.
(1) In the case of a taxpayer that: subsidiary capital includes the taxpayer's proportionate part (see section 3-13.2[a] of this Part) of any stock or indebtedness described in subdivision (a) of this section of such corporation that is owned by such partnership. Example:
(ii) is a partner in a partnership with respect to which the taxpayer uses the aggregate method pursuant to section 3-13.3 of this Part;
Example:
Corporation C is 90 percent partner in partnership P. Corporation D has 100 shares of stock issued and outstanding entitling the holders thereof to vote for the election of the corporation's directors. C owns 60 shares of D and P owns the remaining 40 shares. Since C directly owns more than 50 percent of the shares of D it would include 96 shares of D in its subsidiary capital; its 60 shares plus its proportionate part, 36 shares (90% × 40), of P's shares.
(2) In the case of a taxpayer that: subsidiary capital does not include taxpayer's proportionate part (see section 3-13.2[a] of this Part) of any stock or indebtedness of such corporation owned by such partnership. Such stock or indebtedness is includible in investment capital if it meets the definition of investment capital as set forth in section 3-3.2 of this Part. Otherwise, it constitutes business capital.
Example:
The taxpayer (parent) loaned its subsidiary $100,000. In computing entire net income for the taxable year 1990 for New York State franchise tax purposes under either article 9-A, 32 or 33 of the Tax Law, the subsidiary did not claim any part of the interest as a deduction. The subsidiary did claim such interest, or some part of it, as a deduction for taxable year 1991. The indebtedness is includible in the taxpayer's subsidiary capital on its report for taxable year 1990. However, for taxable year 1991 such indebtedness is includible in the taxpayer's investment capital if it meets the definition of investment capital as set forth in section 3-3.2 of this Part. Otherwise it is business capital.
(e)
Tax Law, § 208(4), (8-A)