1. (a) In all cases where a combined return is permitted or required (see Subpart 21-2 of this Part Combined Returns), a combined franchise tax return must be submitted by the taxpayer designated as the parent responsible for paying the combined tax on form CT-32-A. In addition, each corporation in the combined group must submit such other reports and other information which the commissioner may require.
2. (b) It is not necessary that all corporations in the combined group have the same accounting period. (See Subpart 17-1 of this Title for information relating to accounting periods). Where a corporation’s taxable year is different from that of the taxpayer designated as the parent, the applicable taxable year of such corporation to be included in the combined group is the taxable year that ends within the taxable year of the taxpayer designated as the parent. The commissioner may permit or require a taxpayer to use a different accounting period where appropriate.

Tax Law, § 1462(a)