Since Tax Year 2017, you no longer need to make a payment to the MT Dept of Revenue by the due date of the return to obtain a valid extension. All taxpayers can enjoy a six-month automatic extension. As a result, the department removed the extension checkbox and the extension line on Form 2. However, the automatic extension to file is not an extension to pay . If you pay all or part of your taxes after April 15, 2019, you will have to pay interest at a 5 percent rate on that amount. If you file on extension, you may still want to make a payment before April 15 to reduce the interest you will owe. When making such payments: Choose “Payment with Return” on the Montana Individual Income Tax Payment Voucher or “Return Payment” if you pay via E-check, and Report this payment on line 7 of the “Other Payments and Refundable Credits Schedule” when you file your return.
