The commission, upon a showing of good cause, may grant a reasonable extension of time for filing an assessment return or for the payment of any assessment. Any application for such extension must be made prior to the due date. As a condition of granting an extension of time for filing a return, the commission may require the submission of a tentative return and the payment of the assessment based on such tentative return.
N.Y. Comp. Codes R. & Regs. Tit. 21 § 9.4