4580: Unitary Business Group Combined Filing Schedule (2025)
Michigan · Michigan Treasury · Used for tax years 2025
Form 4580 is the 2025 Michigan Business Tax Unitary Business Group Combined Filing Schedule for Standard Members. It lists the members included in the combined return and reports member information, sales, modified gross receipts, business income, deductions, and credit carryforw
Who files this form
Form 4580 is the 2025 Michigan Business Tax combined filing schedule for standard members of a Unitary Business Group (UBG).
Part 1A lists the members whose activity is included on the combined return, starting with the Designated Member. Include all UBG members, with or without nexus with Michigan, except those excluded in Part 3.
What you'll need
Have the following information ready:
- Each member’s name, FEIN or TR Number, address, organization type, NAICS code, and federal tax period.
- Membership dates for part-year members and the effective date for any discontinued member.
- A description of business activities connecting the members.
- Each member’s sales, gross receipts, business income, deductions, credit carryforwards, and tax payments requested in Part 2A.
- Information about excluded affiliates and standard members included on the prior combined return but not the current return.
Attach a copy of federal Form 851 if you check line 71 because some or all members are included on a consolidated federal income tax return. Also attach Form 851 if any persons listed in Part 3 are part of a federal consolidated group.
If business activity is protected under PL 86-272, line 30 directs you to complete and attach Form 4581 or Form 4586, as applicable.
Common mistakes
- Do not skip the instructions. The form specifically says to read them before completing it.
- If Part 1A needs extra pages, repeat the Designated Member’s name and FEIN or TR Number at the top of each page, but not on line 1.
- Complete a separate Part 1B for each member listed in Part 1A.
- Enter whole dollars only in Part 2A.
- Do not carry every Part 2A line to Part 2B. The form warns that not all lines carry over.
- Leave lines 46, 47, and 68 blank. The form says no amount is to be entered on these lines.
- List a person in both Part 3 and Part 4 if that person meets the criteria for both parts.
Questions people ask
Do members without nexus with Michigan belong in Part 1A?
Yes. Include all UBG members whose activity is included on the combined return, with or without nexus, except those excluded in Part 3.
What if a member has no Michigan sales?
Enter zero on line 14.
Who belongs in Part 3?
List every person, with or without nexus, who satisfies the UBG’s greater-than-50% ownership test but is not included on the combined return of standard taxpayers. Enter the applicable exclusion reason code in column D.
Who belongs in Part 4?
List persons included as standard members in the Designated Member’s immediately preceding combined return who are not included as standard members on the current return. If someone also meets the Part 3 criteria, list them in both parts.