Michigan's property tax calendar is unforgiving. Commercial property owners who miss critical filing windows lose the right to challenge their assessments for an entire year — sometimes longer. Whether you own an office building, a retail property, or an industrial facility, this 2026 deadline guide will help you protect your right to a fair assessment.
Why Michigan Deadlines Matter More Than You Think
Michigan is one of the strictest states in the country when it comes to property tax appeal deadlines. Unlike Ohio or Indiana, where filing windows tend to be more flexible, Michigan's system operates on a rigid annual cycle. The Board of Review meets only once per year in March, and the Michigan Tax Tribunal has firm cutoff dates that cannot be extended. There is no grace period, no late filing provision, and no exception for properties that are clearly over-assessed.
This is especially important for properties that have recently changed hands. Michigan's uncapping rules mean that a property's taxable value can jump significantly after a sale. If you bought a commercial property in 2025 and the assessment uncapped in 2026, you have a narrow window to challenge it.
February 2026: Assessment Notices Mailed
By the end of February, local assessors mail assessment notices to all property owners. These notices show your property's assessed value (which should equal 50% of true cash value) and your taxable value. This is your first indication of whether your taxes will increase and by how much.
When you receive your notice, compare the assessed value to what you believe your property is actually worth on the open market. If the assessed value exceeds half of the fair market value, you have grounds for an appeal. Do not wait — the first deadline is only weeks away. For guidance on gathering evidence, see our guide on property tax appeal evidence.
March 2026: Board of Review Hearings
The March Board of Review is the first (and for many property owners, the only) chance to protest an assessment at the local level. Boards of Review typically meet during the first two weeks of March. The exact dates vary by municipality, but the window is always short.
To appear before the Board of Review, you generally need to file a written protest by the meeting date. Some municipalities require advance notice. The Board has authority to adjust both assessed value and taxable value, making it a valuable step — especially for clear-cut over-assessments. Learn more about the full property tax appeal process in Michigan.
May 31, 2026: Michigan Tax Tribunal (Small Claims) Filing Deadline
If the Board of Review does not reduce your assessment — or does not reduce it enough — you can escalate to the Michigan Tax Tribunal. For the Small Claims Division, petitions must be filed by May 31st. The Small Claims Division handles properties with assessments under a certain threshold and offers a simpler, less formal process.
Note that you must attend the March Board of Review before filing with the Tax Tribunal. This is a prerequisite. If you skip the Board of Review, you lose your right to go to the Tribunal for that tax year.
May 31, 2026: Michigan Tax Tribunal (Entire Tribunal) Filing Deadline
The Entire Tribunal handles larger commercial properties and more complex cases. The filing deadline is also May 31st. Cases before the Entire Tribunal are more formal, involving discovery, expert witnesses, and potentially multi-day hearings. This is where the biggest tax savings are often achieved — but the evidence requirements are substantial.
For high-value commercial properties in counties like Wayne County, Oakland County, or Macomb County, the Entire Tribunal is often the most effective forum. A property tax consultant can help you navigate the process and build a case that holds up under scrutiny.
July 2026: Summer Tax Bills Issued
Summer property tax bills are typically mailed in July. Even if you have an active appeal, you are required to pay your taxes as billed. If your appeal is successful, you will receive a refund for the overpayment. This is an important point — filing an appeal does not defer or reduce your current payment obligation.
December 2026: Winter Tax Bills Issued
Winter tax bills follow in December. The same payment rules apply. Keep records of all payments — you will need them to calculate your refund if your appeal succeeds.
What to Do Right Now
If you own commercial property in Michigan and believe your assessment is too high, the best time to act is now. Review your assessment notice, compare it to recent sales of similar properties, and determine whether an appeal makes sense. For a detailed look at deadlines across all three states, see our property tax deadlines resource.
At EPTA, we handle every step of the appeal process — from reviewing your assessment to representing you before the Board of Review or Tax Tribunal. There is no fee unless we reduce your taxes. Our team has nearly 20 years of experience helping commercial property owners across Michigan, Indiana, and Ohio pay fair property taxes. Learn more about the cost of a property tax appeal and what to expect.
