CIT: Montana Corporate Income Tax Return (Form CIT) (2025)
Montana · Montana DOR · Used for tax years 2025
Form CIT is the 2025 Montana Corporate Income Tax Return. It reports a corporation’s federal taxable income, Montana additions and reductions, income apportioned or allocated to Montana, net operating losses, and Montana tax liability.
What you'll need
Include a copy of your signed federal Form 1120 as filed with the IRS.
Depending on your answers and the amounts you report, you may also need:
- Group filing documents: If you answer Yes to Part I, question 2 or 3, include Schedule M and pages 1 through 5 of the parent’s consolidated federal Form 1120.
- Special filing schedules: Include Schedule K if you claim protection under Public Law 86-272. Water’s Edge filers must have a valid election and include Schedule WE. Limited Combination filers must attach a statement.
- Income adjustments: Include the schedules and detailed breakdowns requested for your additions, reductions, and income allocated directly to Montana.
- Loss documents: Use Schedule NOL to calculate your net operating loss carryover. Include the requested Schedule D for capital loss entries.
- Withholding records: Include Form(s) 1099 for Montana mineral royalty tax withheld and Montana Schedule(s) K-1 for tax withheld from pass-through entities.
- Credit documents: Include Schedule C and the applicable credit forms or other required information.
- Underpayment interest: Include Form CIT-UT when reporting estimated tax underpayment interest.
For an amended return, include the documents requested for your reason for amending, such as a complete federal Revenue Agent Report, federal Form 1120X, Schedule NOL, or a detailed explanation of adjustments. For a final return, include a detailed statement.
Common mistakes
- Using staples: The form says “No Staples.”
- Only changing part of an amended return: Complete the entire form using corrected amounts.
- Leaving gross receipts blank on a paper-filed return: Enter total gross receipts in the space provided.
- Substituting federal Form 851 for Schedule M: Form 851 is not an acceptable substitute for Schedule M’s U.S. consolidated group section.
- Using the wrong calculations for combined filers: Combined filers with more than one entity with Montana activity must use Schedule K-Combined for page 3, lines 5 through 10.
- Including next year’s applied overpayment as a previous refund: Do not include overpayments to 2026 on line 12g.
- Skipping the signature: The form identifies the signature section as required.
Questions people ask
What do I do if I claim protection under Public Law 86-272?
Mark the box in Part I, question 1, complete and include Schedule K, and skip Part I, questions 2 through 5.
When do answers to the general questions require Schedule M?
If you answer Yes to any of Part III, questions g through m, complete and include Montana Schedule M.
Can I request direct deposit of my refund?
The form has a direct deposit section. Enter your routing number and account number, select checking or savings, and mark the box if the refund is going to an account outside the United States or its territories.
Can I apply an overpayment to next year’s estimated tax?
Yes. On the 2025 return, enter the amount you want applied to your 2026 estimated tax on line 15.
Where can I get help with the form?
Call (406) 444-6900. The form also lists Montana Relay at 711 for people with hearing impairments.