Montana State Income Tax Overview

The Department of Revenue for Montana oversees the collection of state income tax from Montana residents as well as those who otherwise earn income from a source based in Montana.  Those who meet the requirements must file a state income tax return with the Montana Department of Revenue.  This tax return is in addition to the federal income tax return filed with the Internal Revenue Service (IRS) each year.

Below are frequently asked questions about Montana state income tax, such as who has to file, tax rates, and due dates for any tax owed.  If you have additional questions about filing federal income tax, visit our “Tax Relief” page.

Who is required to file a Montana state income tax return?

If you are a resident of Montana, you must file a state income tax return on all income earned except from that specifically exempted from state income tax.  If you are not a resident of Montana but earned income during the tax year from a business based in Montana, you must file a Montana state income tax return for the income earned from that business.

If you are a resident of Montana for part of the year, you must file a state income tax return on all income earned during the portion of the year when you reside in Montana and only on Montana-based income earned during the portion of the year when you reside outside of Montana.

How does Montana calculate the amount of tax I owe?

Montana uses what is known as a progressive tax rate, which means that the percent of tax paid increases as your taxable income increases.

Montana uses the following tax rates for calculating tax owe:

Tax Rate Table

If your taxable income is
More than But not more than Then your tax is Less
$0 $2,700 1% of taxable income $0
$2,700 $4,700 2% of taxable income $27
$4,700 $7,200 3% of taxable income $74
$7,200 $9,700 4% of taxable income $146
$9,700 $12,500 5% of taxable income $243
$12,500 $16,000 6% of taxable income $368
More than $16,000 6.9% of taxable income $512

 

When are Montana state income tax returns due each year?

Montana state income tax returns are due on the April 15 following the tax year.  When April 15 falls on a holiday or weekend, Montana state income tax returns must be filed by the first non-holiday business day thereafter.

If you cannot file your tax return by April 15, you can obtain a six-month extension on the filing of your return.  However, the extension only applies to the filing of your tax return, not to the payment of any tax liability owed.  If you do not pay your state income tax by the due date, you will be assessed a penalty of 1.2% of the unpaid balance for each month you are late.  In addition, you will be charged interest on any unpaid tax liability.

Can I obtain help in completing my Montana state income tax return?

Yes, if you need help completing your tax returns from Montana state income tax or federal income tax, you can call the telephone number located at the top of this page.  You will speak with someone who will have a tax attorney contact you who is experienced with federal and Montana state income tax law and can help you complete and file both tax returns.

by Mark Johnston

Mark has been a contributor to legal web sites related to bankruptcy, tax, and criminal law since 2011. He has an Accounting degree from Texas A&M University.