Form6: Form6 (2025)
Wisconsin · Wisconsin DOR · Used for tax years 2025
Wisconsin Form 6 is the 2025 Combined Corporation Franchise or Income Tax Return. It reports combined group income, Wisconsin apportionment, credits, tax payments, and the resulting amount due or refund.
Who files this form
Wisconsin Form 6 is the Combined Corporation Franchise or Income Tax Return for 2025. It reports information for a Wisconsin combined group.
Do not use this form if you are filing as a single entity. The supplied form does not explain the full rules for determining which corporations must join a combined group.
When it's due
For tax year 2025, the form states that the return is generally due on the 15th day of the fourth month following the close of the taxable year. It refers filers to the instructions for details, but no instructions were supplied.
What you'll need
- A copy of your federal return. Include it with Form 6 even if there was no Wisconsin activity.
- Federal return information for the group. The reconciliation asks for company names, federal employer identification numbers (FEINs), and amounts from federal Form 1120, line 28.
- Member information. Have each member’s name, FEIN, address, Wisconsin DFI number, NAICS code, state and year of incorporation, and tax-period information available.
- Applicable supporting forms and schedules. The form references apportionment schedules, Form N, Form 6CL, Form 6BL, credit schedules, and Schedule CF, among others, for amounts reported on the return.
- Required explanations and attachments. Include Schedule AR for an amended return. Attach a statement explaining other federal-law adjustments reported in Part I, line 34, and schedules for asset-basis differences reported in Part II, lines 2g or 4k, if applicable.
How to file
Form 6 must be filed electronically. The supplied form is marked “Sample Form” and “File Electronically.”
Include a copy of the federal return and applicable attachments. The form provides signature and date fields for an officer and the preparer.
The supplied text does not give an electronic filing website or a mailing address.
Common mistakes
- Using Form 6 to file as a single entity. The form expressly says not to do this.
- Filing on paper instead of electronically. Electronic filing is required.
- Leaving out the federal return because there was no Wisconsin activity. A copy is still required.
- Omitting Schedule AR when filing an amended return.
- Entering nonrefundable credits in Part V, line 3e, that exceed the member’s gross tax on line 2. The printed note says those credits should not exceed that tax.
Questions people ask
Can an overpayment go toward next year’s estimated tax?
Yes. On the 2025 return, enter the portion of line 28 you want credited to 2026 estimated tax on line 29. Subtract line 29 from line 28 to calculate the refund on line 30.
Can someone else discuss the return with the department?
Yes. Select “Yes” in the Third Party Designee section and provide the designee’s name, personal identification number (PIN), and phone number.
What should I include with an amended return?
Check the amended-return box, attach an explanation, and include Schedule AR. Page 1 also has lines for amounts previously paid and previously refunded.
What if no group members filed a federal consolidated return?
The reconciliation section says to skip line 1 and go to line 2.