N.Y. Comp. Codes R. & Regs. Tit. 20 §§ 7-3.5
(Tax Law, section 213-b(c) and (h))
If any amendment of a declaration is filed, the remaining installments, if any, must be ratably increased or decreased (as the case may be) to reflect any increase or decrease in the estimated tax by reason of such amendment. If an amendment is made after the 15th day of the ninth month of the current taxable year, any increase in the estimated tax must be paid at the time of making such amendment.
On June 15, 2022, Corporation Y files a declaration of estimated tax of $14,000 for the 2022 taxable year. Corporation Y has already paid a mandatory first installment of $2,000 on March 15, 2022, and divides the $12,000 of remaining estimated tax by three to compute the $4,000 installment amount to be paid on June 15, on September 15, and on December 15. Corporation Y paid the required $4,000 installment on June 15, 2022. On September 15, 2022, it files an amended declaration showing an estimated tax of $20,000 for the 2022 taxable year. The balance of $14,000 ($20,000 minus $2,000 mandatory first installment and $4,000 June estimated payment) must be paid in two remaining installments: $7,000 on September 15, 2022, and $7,000 on December 15, 2022.
N.Y. Comp. Codes R. & Regs. Tit. 20 §§ 7-3.5