40-X: Form 40-X - Amended Corporation Income Tax Return (Revision 2016-11)
North Dakota · ND Tax Commissioner · Used for tax years 2024, 2025
North Dakota Form 40X is an amended corporation income tax return used to correct a previously filed Form 40. It reports changes to income, deductions, tax credits, and tax liability, along with any additional payment due or refund.
Who files this form
A corporation must file North Dakota Form 40X to amend a previously filed return if:
- It files an amended federal income tax return.
- A federal audit changes its federal taxable income or federal income tax liability.
- A North Dakota loss carryback changes its North Dakota income, subject to the rules for line 13.
- It wants to correct an error on a previously filed return.
- It receives a refund of federal income tax that it deducted on a previously filed return.
What you'll need
Prepare or gather:
- A corrected Form 40, page 1, and supporting schedules for the year being amended. Use that year's forms and schedules.
- Only the corrected North Dakota schedules from this list: FACT, FACT-1, SA, CR, FTD, TC, WE, WW, AMT-C and AMT-R.
- A complete copy of the amended federal return, Federal Form 1139 or Federal Revenue Agent Report, as applicable.
- An explanation of all changes to tax credits.
- Supporting schedules for exempt income from a new or expanding business, or Schedule RZ for exempt renaissance zone income, if applicable.
If the corporation is included in a consolidated federal return, also attach:
- Its amended pro forma separate-company federal return.
- Pages 1 through 4 of the amended consolidated federal return.
- The schedule of gross income and deductions by company supporting the amended consolidated taxable income.
You will also need the corporation's federal employer identification number, the name used on the original Form 40, and the amounts originally reported or later adjusted.
How to file
- Prepare the corrected Form 40, page 1, and required schedules for the year being amended.
- Complete Form 40X. Enter the tax period, corporation information and reason for the changes. Mark the original return's filing method.
- Use Column A for amounts originally reported or adjusted, Column B for the net increase or decrease, and Column C for the correct amounts. Use the tax brackets and rates for the year being amended.
- Attach the corrected Form 40, page 1, and required state and federal documents. Complete the officer's signature, title and date fields, and the preparer fields if applicable.
- Mail the completed return to:
Office of State Tax Commissioner
600 E. Boulevard Ave., Dept. 127
Bismarck, ND 58505-0599
Any total payment due must be paid when the return is filed. Payment may be made by check or money order payable to the North Dakota State Tax Commissioner. Payment is not required if the tax due is less than $5.
Common mistakes
- Leaving out required attachments. The instructions warn that the return is incomplete without all required state and federal attachments.
- Omitting the identification number. Disclosure is mandatory. A missing social security number or FEIN may delay or prevent processing.
- Using the wrong year's forms or tax rates. Use forms, schedules, tax brackets and rates for the year being amended.
- Changing tax credits without an explanation. Attach an explanation for every change to credits.
- Expecting a refund under $5. The form states that no refund under $5 will be issued.
Questions people ask
Do I need a corrected Form 40 as well as Form 40X?
Yes. Prepare and attach a corrected Form 40, page 1, along with the required corrected schedules for the year being amended.
Can I let the tax office discuss the return with my preparer?
Yes. Mark the authorization circle in the signature area. It applies only to the individual who signed as preparer, not the preparer's firm. The authorization ends automatically six months after the amended return is filed.
Does preparer authorization let my preparer receive the refund?
No. It does not authorize the preparer to receive a refund check, bind the corporation to additional tax liability or otherwise represent it before the tax office. Expanded authorization requires a signed and filed North Dakota Form 500.
Where can I get forms or help?
Visit www.nd.gov/tax, email corptax@nd.gov or call 701.328.1249. For speech and hearing assistance, call Relay North Dakota at 1.800.366.6888.