Due Dates
- Returns
- April 15
- Extension
- October 15
Tax Types
Individual Income TaxYour filing status is your marital status for tax filing purposes. Your standard deductions, filing requirements, and other aspects of your tax return may change based on your filing status.
Montana recognizes four filing statuses:
- Single
- Married filing jointly
- Married filing separately
- Head of Household
Choose your status based on which fits you best on December 31 of the tax year. If more than one status applies, choose whichever status gives you the lowest taxes.
Selecting a Filing Status
Single
You are single if:
- You were never married;
- You were legally separated according to your state law under a final decree of divorce or separate maintenance; or
- You were widowed before January 1 of the tax year and did not remarry during the tax year.
Married Filing Jointly
You and your spouse may file a joint return if:
- You were married as of December 31 of the tax year even if you did not live with your spouse at the end of the tax year;
- Your spouse died during the tax year and you did not remarry during the tax year; or
- You were married as of December 31 of the tax year and your spouse died in the following tax year before filing a tax return.
Married Filing Separately
If you and your spouse both have income, you can file your Montana income tax returns separately, even if you filed your federal income tax jointly.
If you choose to file separately, you will need to report your adjusted gross income separately. You can’t assign income between the two of you.
Each spouse should report income from their own employment or work as independent contractors.
If you own property generating rent, royalty, or dividend income, report the income on your return. If you and our spouse both own part of the property, any rent, royalty, or dividend income, split the income equally unless you can show a different proportional ownership.
When you file separately, both spouses claim either the standard deduction or their own itemized deductions.
On the Same Form
You may file separately on the same form unless one spouse is a Montana resident, and the other is not.
Although you’re submitting returns on the same form, you are submitting two separate tax returns. If both taxpayers are entitled to refunds, we will issue two separate checks or direct deposits. If both spouses owe additional tax, penalties, or interest, we will mail separate Statements of Account.
Please Note: If you file separately on the same form, we assume you want us to apply your refund to your spouse’s amount owed. Please file on separate forms if you do not want your refund offset against your spouse’s taxes.
If we discover math or other computational errors when processing the form, we will adjust it to correct the error. This might cause your refund to be applied to your spouse’s increased tax. To avoid this, file your returns on separate forms.
On Separate Forms
- Both of you have Montana source income and one spouse is a resident of Montana and the other spouse is a nonresident; or
- You want to receive your own refund or pay your own tax.
Spouse Not Filing
You can use this filing status if:
- Both you and your spouse are nonresidents and one spouse has no Montana source income,
- You are a resident and your spouse is a nonresident with no Montana source income,
- Another taxpayer claims your spouse as a dependent.
When you use this status, you can’t claim your spouse as an exemption on your return.
Head of Household
You can file as head of household if you qualify on your federal income tax return. See the IRS guidelines for more information.