Michigan Business Tax Extension 2026: 2025 Tax-Year Filing Guide
LLC & Partnership · S Corporation · C Corporation · Fiduciary
This guide explains how to file a Michigan (MI) business tax extension for each entity type. For example, CBT taxpayers generally receive six months, while partnerships generally receive five months. However, estimated tax remains due by the original deadline.
Need a pro? Connect with a U.S.-based CPA or EA to prepare and file your MI return.
Remember, payment is still due by the original deadline. In other words, extensions only extend filing time.
Michigan (MI) rules depend on entity type. Confirm the entity classification, file the required extension or retain federal proof when applicable, and pay required tax by the original deadline.
Michigan LLC / Partnership Tax Extension: Filing Details
Michigan filing requirements depend on whether the LLC or partnership is subject to CIT, flow-through withholding, or another Michigan tax. For the 2025 calendar-year return, the extended filing deadline is Varies by tax.
In addition, the extension applies to filing time only. Therefore, pay required Michigan tax by the original deadline to limit penalties and interest.
The extension applies to filing time only. Pay required Michigan tax by the original deadline to limit penalties and interest.
Michigan S Corporation Tax Extension: Filing Details
Michigan S corporations and flow-through entities should use the current Treasury forms and instructions for the applicable tax. For the 2025 calendar-year return, the extended filing deadline is Varies by tax.
Michigan C Corporation Tax Extension: Filing Details
A calendar-year 2025 Michigan CIT annual return is due April 30, 2026. A properly filed and paid Form 4 can provide an eight-month extension to December 31, 2026. For the 2025 calendar-year return, the extended filing deadline is Dec. 31, 2026.
The extension applies to filing time only. Pay required Michigan tax by the original deadline to limit penalties and interest.
Michigan Fiduciary / Estate / Trust Tax Extension: Filing Details
Michigan fiduciary and trust filings use their own return requirements. Confirm the current Treasury form and deadline. For the 2025 calendar-year return, the extended filing deadline is See Treasury guidance.
Quick Reference: Deadlines and Forms
The table below provides a quick reference to Michigan business tax extensions. See our IRS Form 7004 guide, Michigan individual tax extension, and business tax extension resource for related guidance.
| Entity Type | NJ Return Form | Extension Method | Extended Deadline |
|---|---|---|---|
| LLC / Partnership | State business return / State business return | Federal 5-month; State extension form / State extension form | Sept. 15, 2026 |
| S Corporation | State business return | State extension form | Oct. 15, 2026 |
| C Corporation | State business return / State business return | State extension form | Oct. 15, 2026 |
| Fiduciary / Estate / Trust | State fiduciary return | Form State fiduciary extension | Oct. 15, 2026 |
Frequently Asked Questions
Quick answers about Michigan business tax extensions – but always confirm the current rules with the Michigan Division of Taxation.
Visit MI tax agencyYes. However, the applicable entity-specific requirements listed above must be satisfied. Michigan grants extensions to LLCs, partnerships, S corporations, C corporations, and fiduciaries, but the rules – including which form to file, how long the extension lasts, and the payment threshold – vary by entity type.
Generally no. In other words, pay required tax by the original deadline and confirm the current state payment rules. An extension of time to file does not extend the time to pay – failing to pay by the original deadline can result in penalties and interest, even if the return is filed within the extended window.
No. In practice, partnerships, S corporations, C corporations, and fiduciaries can use different original dates, extension periods, or forms. For 2025 calendar-year returns filed in 2026, partnerships and LLCs taxed as partnerships get a five-month extension (Sept. 15), while the others generally get a six-month extension (Oct. 15).
Review the Michigan Division of Taxation guidance for the entity’s return. Additionally, the DOR publishes the most current forms (State extension form, State extension form, State fiduciary extension, etc.) and any changes to extension periods or payment thresholds.
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