You can be granted an extension of time for filing your Montana tax return if you meet both of the following requirements by April 15:
1. You have applied to the Internal Revenue Service by filing federal Form 4868 for an automatic six-month extension to file your federal tax return.
2. You have paid 90% of your Montana income tax liability or 100% of the amount of your Montana income tax liability from last year through your estimated tax payments, your withholding tax, or a combination of both your estimated and withholding tax payments.
Even though you have applied for an automatic six-month federal extension, this does not guarantee that you have a Montana extension unless you have met one of the requirements listed in number 2 above on or before April 15. You should examine and use the Montana Form EXT-09, which is the Extension Payment Worksheet, in order to determine whether you have a Montana extension payment requirement. You can get a copy of this form by visiting our website at revenue.mt.gov or calling us toll free at (866) 859-2254 (in Helena, 444-6900).
If you are required to make an extension payment, please use the tax payment voucher found on this worksheet.
In order to complete your Montana extension, you have to check the extension indicator box found on the bottom right hand corner of Form 2, page 2 and attach a copy of your federal Form 4868, Application for Automatic Extension of Time to File U.S. Individual Income Tax Return, to your Montana tax return. If you file electronically, you do not have to send the federal Form 4868 to us but you should keep a copy for your records. Please do not send us a copy of your federal Form 4868 prior to filing your Montana tax return.
It is important that you follow the requirements stated above, or your extension will not be accepted and a late file penalty will be applied.
Please be aware that any extension of time to file your Montana tax return is not an extension of time to pay your income tax liability. If you have a valid Montana extension but have not paid your complete income tax liability by April 15, you are relieved of late file penalties but you are not relieved of late payment penalties and interest on your outstanding Montana income tax liability.