(1) Payments of estimated tax with respect to short taxable years are to be made at the times and in the amounts required for regular tax years as listed in 15-31-502 , MCA, except that any installment that is not paid before the 15th day of the last month of the short taxable year must be paid on that date. For example:

(a) Corporation X, a calendar year corporation, changes to a fiscal year starting September 1. Corporation X was required to make estimated payments for the short tax year covering the periods from January 1 through August 31. Corporation X was required to make two 25% installments of estimated tax, the first on or before April 15, and the second on or before June 15, and had to pay 50% of the estimated tax on or before August 15 (the 15th day of the last month of the short tax year) , as the last installment.

(2) If the tax period was three months or less, there would be no quarterly estimated payment requirement.