The Miscellaneous Forms section contains Montana forms that may be needed for special filing situations, such as making estimated tax payments, requesting an extension, or calculating penalties.
What Can Be Found in the Miscellaneous Forms Section?
Estimated Payment Vouchers (Form IT)
Form IT is used to generate estimated tax payment vouchers for taxpayers who expect to owe Montana income tax and need to make payments throughout the year.
Estimated payments are commonly made by taxpayers who:
- Are self-employed
- Receive income not subject to withholding
- Expect to have a balance due when filing their return
Underpayment of Estimated Tax
You are required to pay your income tax liability throughout the year. You can make your payments through employer withholding, installment payments of estimated taxes, or a combination of both. If you do not pay 90% of your 2025 income tax liability in advance after applying your credits or 100% of your 2024 income tax liability after applying your credits, you may have to pay interest on the underpayment of your estimated taxes with your return.
You may use Form EST-I to calculate the interest on the underpayment of your estimated taxes.
Penalties, Interest & Tax Recapture
Late File Penalty: If you file your return after the extended deadline (October 15), you are assessed a late filing penalty. The penalty is equal to 5% per month on the amount owed by October 15, up to 25% of that amount, until the return is filed. The minimum penalty is $50, even if you are claiming a refund.
Late Payment Penalty: Tax paid after the due date, April 15, 2026, is subject to a late payment penalty equal to 0.5% per month, calculated daily, from April 15, 2026, until it is paid.
Interest Penalty: If you do not pay 100% of your tax by April 15, 2026, you are assessed 7% annual interest, compounded daily on the amount you owe. Multiply your amount owed by 0.000192 for each day your payment is late. If you made payments after April 15, you must adjust the amount owed after each payment for the calculation of interest.
First-Time Homebuyer Account Penalty: If you withdrew fund from your First-Time Homebuyer account for purposes other than to pay for eligible costs for the purchase of a single-family residence, you must pay a 10% penalty on this withdrawal unless the withdrawal was made on the last business day of the year.
Farm and Rach Risk Account Penalty: If you have not distributed your deposits and income from your Farm and Ranch Risk Management Account within three years, they are considered distributed and subject to a 10% penalty.
Medical Care Savings Account Penalty: If you withdrew funds from your Medical Savings Account for purposes other than to pay for eligible medical expenses, you must pay a 10% penalty on this withdrawal unless it was made on the last business day of the year.
Lump-sum and recapture taxes: Report the total amount of lump sum tax and recapture taxes.
- Family Education Savings
- Endowment Credit Capture
- MT Achieving a Better Life Experience
- Biodiesel/Oilseed Recapture
- Trades Education and Training Credit Recapture
- Lump Sum Taxes
For additional information about Lump-Sum and Recapture Taxes, click here.
Montana Extension Form
Montana grants an automatic 6-month extension for filing a return. The extension only extends your time to file but does not apply to payments. All payments are due by April 15, 2026.
If you need to make an Extension payment, you may do so using this form. This form will not be submitted electronically with your return, and you will need to mail this form to the appropriate address listed on the form/instructions.
Program Entry
- State
- Edit
- Miscellaneous Forms