N.Y. Comp. Codes R. & Regs. tit. 20, § 4-1.1
(a) Article 9-A of the Tax Law provides for separate allocations of business income and business capital, investment income and investment capital, alternative business income, alternative investment income, and subsidiary capital. Business income is defined in section 4-8.2 of this Part, business capital is defined in section 3-3.3 of this Title, investment income is defined in section 4-8.3 of this Part, investment capital is defined in section 3-3.2 of this Title, alternative business income is defined in section 210(3-a)(e)(i) of the Tax Law, alternative investment is defined in section 210(3-a)(e)(ii) of the Tax Law and subsidiary capital is defined in section 3-6.3 of this Title.
Except for corporations principally engaged in the conduct of aviation or in the conduct of a railroad or trucking business (see subdivisions [c] and [d] of this section), all taxpayers allocate within and without New York State their business income and business capital pursuant to Subpart 4-2 of this Part and their alternative business income pursuant to section 210(3-a)(a) of the Tax Law. All taxpayers allocate within and without New York State their investment income and investment capital pursuant to Subpart 4-7 of this Part, their alternative investment income, pursuant to section 210(3-a)(b) of the Tax Law and their subsidiary capital pursuant to Subpart 4-10 of this Part. A professional service corporation must allocate its investment income, alternative investment income and investment capital 100 percent to New York State.
(b) Except for corporations principally engaged in the conduct of aviation or in the conduct of a railroad or trucking business, business income and business capital are allocated by a “business allocation percentage” and alternative business income is allocated by an “alternative business allocation percentage,” both determined by a three-factor formula consisting of:
(Tax Law, § 210)