DR 0112X: Amended C Corporation Income Tax Return (2025)
Colorado · Colorado DOR · Used for tax years 2025
Form DR 0112X is used to correct a 2025 Colorado C Corporation income tax return. It reports the corrected tax calculation and any resulting amount owed, refund, or overpayment credited to estimated tax.
Who files this form
Use the 2025 Colorado DR 0112X to correct a corporation’s 2025 Colorado C corporation income tax return.
The form includes reasons such as a Federal Revenue Agent Report, investment tax credit carryback, federal net operating loss carryback, protective claim, or another reason explained with the return. Colorado net operating losses cannot be carried back to an earlier tax year.
What you'll need
Submit all required schedules and supporting certifications, even if they have not changed from the original return.
Have these items available, as applicable:
- Corporation name, address, Colorado Account Number and FEIN.
- Federal taxable income from Form 1120, line 30; Form 1120X, line 3c; or Form 990-T, Part I, line 11.
- The original return or previous adjustments, if you are calculating the revised refund or balance due yourself.
- DR 0112RF for receipts-factor or special-rule apportionment, and Schedule C for the group filing categories that require it.
- Required credit forms, such as DR 0112CR, DR 1366, DR 1370, DR 1330, DR 1305G, DR 0617, DR 1307 and DR 0619, when applicable.
- W-2G forms for lottery withholding and a copy of the assessor’s statement for the Business Personal Property Credit, when applicable.
- Required credit certificates, including the Office of Economic Development certificate for Credits for Employee-Owned Businesses and Colorado Energy Office certificates for Certified Greenhouse Gas Avoidance Credits.
- Explanations required for your entries. For a protective claim, include a statement identifying and describing the contingencies on which the claim depends.
How to file
File online
File the return for free through Revenue Online at Colorado.gov/RevenueOnline. You can also pay online, though certain payment methods may have a small processing fee.
Complete the return
Use the form for the tax year being amended. Select the reason for amending, complete the applicable entries and attach all required supporting documents. Continue through page 5 and complete the officer’s signature, title and date fields.
For questions about income, deductions, modifications or credits, refer to the DR 0112 instructions and associated schedules.
File on paper
You may file on paper if you cannot file electronically, but paper filing may delay processing.
With payment, mail to:
Colorado Department of Revenue
Denver, CO 80261-0006
Without payment, mail to:
Colorado Department of Revenue
Denver, CO 80261-0005
No street address is required for these Department of Revenue addresses.
Pay by check
Make checks payable to Colorado Department of Revenue. Write the tax year and your FEIN or Colorado Account Number on the memo line.
If filing on paper, include payment with the amended return. If filing electronically but paying by check, use DR 0900C to remit the payment.
Common mistakes
- Using the wrong year’s form. The Department cannot process an amended return that does not match the tax year being amended.
- Leaving out unchanged schedules or certifications. Required documents must still be submitted. Missing documentation will cause processing delays and disallowance of credits, subtractions or reduced apportioned income.
- Trying to carry back a Colorado net operating loss. Colorado net operating losses cannot be carried back to an earlier tax year.
- Stopping before page 5. The form reminds filers to continue through page 5 to complete the return.
- Omitting identifying information on a check. Without the tax year and FEIN or Colorado Account Number, the payment might not be properly credited.
- Overlooking the consolidated-report election warning. The election is binding for four years. If made in a prior year, enter the election year.
Questions people ask
Can the Department calculate my refund or balance due?
Yes. After completing line 47, leave lines 48 through 63 blank if you want the Department to calculate and mail your refund or calculate your balance due and mail a bill. You still need to complete the return through page 5.
Can I apply an overpayment to next year’s estimated tax?
Yes. Enter the amount to carry forward on line 62. Line 63 is the refund claimed after subtracting line 62 from the overpayment on line 61.
Do I need to resubmit schedules that have not changed?
Yes. All required schedules and supporting certifications must accompany the amended return, even when unchanged.
How do I identify a protective claim?
Check the protective claim box under the reason for filing. Include a statement identifying and describing the future contingencies on which the claim depends.