NEW
E-File Mandate: Corporations are required to electronically file for all tax periods beginning after December 31, 2022 (SB 24). Corporations must use an approved corporate income tax software provider to e-file their Montana Corporate Income Tax return.
E-File Mandate does not apply if:
Any C corporation doing business in Montana has to file a Montana Corporate Income Tax Return (Form CIT) and pay a corporate income tax.
If you make a Subchapter S election at the federal level, you must also file as an S Corporation in Montana.
Montana corporate tax rates are:
Standard Rate | 6.75% |
---|---|
Water's Edge Election | 7% |
A corporation can apply for approval to take the water's edge election by submitting a Water's Edge Election request on our TransAction Protal (TAP). (15-31-322, MCA) | |
Alternative Gross Sales | The alternative gross sales tax rate is 0.5% on sales in Montana. (15-31-122, MCA) |
To qualify, a corporation must:
| |
Minimum Tax | $50 |
See 15-31-121, MCA for more details.
Your Montana Corporate Income Tax Return (Form CIT) is due:
Calendar Year | May 15 |
---|---|
Fiscal Year | The 15th day of the 5th month following the fiscal year end. Example: If your tax year ends on September 30, your return is due on February 15. |
If a due date falls on a weekend or holiday, it is due on the next business day.
Montana grants all C corporations an automatic six-month extension to file a return. This means extensions are due:
Calendar Year | November 15 |
---|---|
Fiscal Year | The 15th day of the 11th month following the fiscal year end. Example: If your tax year ends on September 30, your return is due on August 15. |
Extension deadlines are for returns only.
Any tax liability must still be paid by the original due date or it will be subject to uniform penalties and interest.
Montana has adopted sections of the Multistate Tax Compact guidelines for determining what share of business income is reportable to Montana. Income will either be apportioned to Montana using an apportionment formula or directly allocated to Montana. See section 15-31-301 to 312, Montana Code Annotated, for more information on determining apportionable and non-apportionable income.
For tax periods beginning on or before June 30, 2021, Montana used an equally-weighted 3 factor apportionment formula consisting of property, payroll, and receipts.
For tax periods beginning after June 30, 2021, the apportionment formula has been changed to use a double-weighted receipts factor. This new formula consists of property, payroll, and the receipts factor counted twice.
See Montana Source Income for more details on apportionment and allocation of income.
For periods beginning after December 31, 2024 the apportionment formula will include only the receipts factor.
Montana Corporate Income Tax Treatment of International Tax Provisions under Tax Cuts and Jobs Act of 2017 (Read Online) (PDF, 515 KB)
If your business estimates owing $5,000 or more, you will need to make quarterly estimated tax payments.
Estimated payments are due on the 15th of the fourth, sixth, ninth, and twelfth months of your tax year.
Example
If your tax year ends on December 31, your estimated payments are due:
First Payment | April 15 |
---|---|
Second Payment | June 15 |
Third Payment | September 15 |
Fourth Payment | December 15 |
If a due date falls on a weekend or holiday, it is due on the next business day.
If a corporation doesn't make estimated payments, it may be subject to penalties and interest. You can calculate these using the Underpayment of Estimated Tax by Corporation (Form CIT-UT).
You must file a Montana Corporate Income Tax Return (Form CIT) every year you do business in Montana.
You may:
If you have no business activity during the tax year, you may file an Affidavit of Inactivity for Corporations, Partnerships and Disregarded Entities through TAP.
See the Montana Form CIT Corporate Income Tax Booklet for more details on filing Corporate Income Tax.
The Corporate Income Tax is subject to uniform penalties and interest.
Corporate income tax goes into the state general fund.