MO-1120: Corporation Income Tax Return (2025)
Missouri · Missouri DOR · Used for tax years 2025
Form MO-1120 is Missouri’s Corporation Income Tax Return for 2025. It reports federal taxable income, Missouri income adjustments, corporation income tax, credits, and payments to calculate a refund or amount due.
What you'll need
Have your corporation’s name, address, charter number, Missouri tax ID number, federal employer ID number, and tax-period beginning and ending dates ready.
The form uses figures from Federal Form 1120, including Line 30 and Schedule J. Depending on your return, you may also need:
- Approved federal extension: Attach a copy of the approved Federal Extension, Form 7004.
- Income not all from Missouri: Complete and attach Form MO-MS.
- Tax credits: Attach Form MO-TC.
- Missouri low-income housing credit recapture: Attach a copy of Federal Form 8611.
- Interest from exempt federal obligations: Attach a detailed schedule.
- Consolidated federal and separate Missouri returns: Attach consolidated Federal Form 1120, Schedule J, and an income statement or summary of profit companies.
- Certain amended carryback returns: Consolidated federal and separate Missouri filers must attach the federal carryback documentation, consolidated income statements, and federal income tax adjustment computations specified in Part 5.
How to file
- Enter the corporation’s identifying information and tax period. Select the boxes that apply to the return.
- Complete the income and tax calculations. Use Page 3 for Missouri additions and subtractions and Page 4, Part 3, for the current-year federal income tax calculation.
- Enter credits and payments, then calculate the refund or amount due.
- Complete the signature section, including the officer’s signature and the preparer information, and attach the required documents.
- For an amended return, select the reason in Part 4. File a separate Form MO-1120 for each reason and complete Part 5 if an applicable carryback is involved.
Mail a return with a balance due to:
Missouri Department of Revenue
PO Box 3365
Jefferson City, MO 65105-3365
Mail a return with a refund or no amount due to:
Missouri Department of Revenue
PO Box 700
Jefferson City, MO 65105-0700
Common mistakes
- Not marking an address change: The form warns that mail may go to the last address on file if you do not select the address change box.
- Missing consolidated-return attachments: For consolidated federal and separate Missouri returns, the federal income tax deduction may be reduced to zero if the required information is not sent.
- Entering an NOL carryover in the wrong place: Page 3, Part 1, Line 3 says not to enter an NOL carryover. Part 2, Line 9 says to enter only a previously disallowed NOL carryback.
- Combining amendment reasons: Part 4 requires one reason to be selected and a separate Form MO-1120 for each reason.
- Overlooking missing paid-preparer information: If a paid preparer failed to sign or provide their IRS preparer tax identification number, answer the form’s question and enter their name, address, and phone number in the applicable signature-block fields.
Questions people ask
What tax rate does the 2025 form use?
Line 14 calculates corporation income tax as 4% of Missouri taxable income on Line 13.
What should I do if I have an approved federal extension?
Select the approved federal extension box and attach a copy of the approved Federal Extension, Form 7004.
Can I apply an overpayment to next year’s estimated tax?
Yes. Line 26 lets you apply part or all of the overpayment on Line 24 to your 2026 estimated tax. Line 27 calculates the refund after subtracting contributions on Line 25 and the amount applied on Line 26.
How can I contact the Department about corporation income tax?
The form lists corporate@dor.mo.gov and (573) 751-4541. It also directs readers to dor.mo.gov/taxation/business/tax-types/corporation-income/ for additional information.