1. (a) Except for corporations principally engaged in the conduct of aviation or in the conduct of a railroad or trucking business, the taxpayer's business allocation percentage is generally computed on the basis of a formula consisting of three factors. The three factors, expressed as percentages, are:

   1. (1) real and tangible personal property within and without New York State, including real and tangible personal property rented to the taxpayer (Subpart 4-3 of this Part);
   2. (2) business receipts within and without New York State (Subpart 4-4 of this Part); and

   3. (3) payroll within and without New York State (Subpart 4-5 of this Part).

      (b)

   4. (1) The business allocation percentage is computed by adding the percentages allocated to New York State during the period covered by the report of the taxpayer's real and tangible personal property factor, business receipts factor, payroll factor and an additional factor equal to the business receipts factor, and dividing the total by four. If either the property or payroll factor is missing, the three remaining factors are added and the sum is divided by three, and if the property factor and payroll factor are both missing, the receipts factor is the business allocation percentage. A factor is not missing merely because its numerator is zero, but a factor is missing if both its numerator and its denominator are zero. The business allocation percentage of a corporation principally engaged in the conduct of aviation or in the conduct of a railroad or trucking business is computed pursuant to section 210(3)(a)(7)(A) or 210(3)(a)(8) of the Tax Law, respectively.
   5. (2) A taxpayer is principally engaged in the conduct of aviation or in the conduct of a railroad or trucking business if, during the taxable year, more than 50 percent of its gross receipts are derived from the conduct of aviation or from the conduct of a railroad or trucking business, respectively. In the case of a taxpayer that is a partner in a partnership using the aggregate method pursuant to section 3-13.3 of this Title, the taxpayer must take into account its gross receipts during the taxable year and its distributive share of gross receipts from the partnership during the applicable partnership year. In the case of a taxpayer that is a partner in a partnership for which an election has been made with respect to such partnership pursuant to the provisions of section 3-13.5 of this Title, the taxpayer must take into account only its distributive share of gross receipts from the partnership during the applicable partnership year.
2. (c) If it appears that the business allocation percentage computed on the basis of all or any of the property-receipts-payroll factors or all or any of the factors applicable to a corporation principally engaged in the conduct of aviation or in the conduct of a railroad or trucking business does not properly reflect the activity, business, capital or income of the taxpayer in New York State, the Commissioner may adjust the business allocation percentage, as set forth in section 4-6.1 of this Part.
3. (d) For computation of the business allocation percentage when a taxpayer is subject to tax for a period less than its taxable period for Federal income tax purposes, see section 4-6.4—Short period business allocation percentage and short period alternative business allocation percentage.

Tax Law, § 210(3)(a) and (8)