Michigan's Nov. 12 tax cutover moves some filers and not others. Split migrations live or die on the which-door page

Who moves, who stays

Michigan's Department of Treasury announced on October 30 that its eServices platform will take on more taxes starting November 12, 2026. It's a sensible modernization, and Treasury has been clear about it. It's also a good example of the hardest kind of migration to explain: one where some people move and others don't.

Here's the split, from Treasury's release.

Moving into eServices on November 12:

• Treasury-administered City income taxes. City of Detroit taxpayers and businesses get full online services, including filing, paying and business registration.
• Wholesale Marijuana Tax, which gains online filing on top of payments.
• Marijuana Retailers Excise Tax. Marijuana retailers move from Michigan Treasury Online.
• Bulk filers for City Employer Withholding Tax, also moving from Michigan Treasury Online.
• Motor Fuel Tax and Tobacco Tax. The Michigan Motor Fuel and Tobacco Tax System, MiMATS, merges into the new platform.
• 9-1-1 accounts.

Staying where they are: sales, use and withholding tax filing through Michigan Treasury Online, known as MTO.

Read that list again as a business owner. A cannabis retailer in Detroit may now have city taxes and the retailer excise tax in eServices, and sales tax still in MTO. A fuel distributor leaves MiMATS behind. Most small businesses that only file sales, use and withholding see no change at all, except closed phone lines for a few days.

The dates that matter this week

Treasury lists staggered closures before the switch:

• Web platform outages began at 5 p.m. on October 30. Treasury points to its Web Platform Impacts page for system-by-system details.
• Certain phone services had limited availability on November 2.
• Business taxes call centers are closed November 4-5.
• Individual Income Tax call centers are closed November 5-6.
• Call centers for City income taxes, Marijuana taxes, Motor Fuel and Tobacco taxes, and miscellaneous taxes and fees are closed November 4-6.
• Collections call centers offer limited services November 4-6.
• All systems resume on November 12.

Treasury's advice to filers is plain: make payments or submit returns before the transition, and review the instructions for your specific tax type. People with existing MiLogin profiles may be able to use their current sign-in.

If you're a filer, the practical step is a short list. Write down every Michigan tax you file, mark each one "moving" or "staying," and for anything moving, check whether you need to do something before or after the 12th. If you have a payment due in the window when the phones are off, don't wait for it.

What every split migration gets asked

Now the part for anyone who runs systems like this, in a state agency, a city, or a company with thousands of customers on an old portal.

When a migration moves everyone, the message is simple: here's the new place, here's the date. When it splits people, every person's question is a version of the same thing: "Is this me?" And they can't easily answer it from a list of system names, because people don't think of themselves as "MiMATS users" or "MTO filers." They think "I run a gas station" or "I do payroll for a restaurant in Detroit."

In a split migration, nobody's question is about the system. It's about themselves.

That's why the most useful thing an agency can publish is a which-door page: one page, sorted by what people file or who they are, that tells each group where to go, what changes for them, what they need to do and by when. Treasury's release already contains the raw material. The page just reorganizes it around the reader.

We wrote about Michigan's unemployment system going dark for a week during its own transition. The lesson there was about planning around the outage. This one is about the sorting.

How we'd build the which-door page

Start from the people, not the platforms.

1. List the groups by what they do. "Marijuana retailer," "Detroit business," "fuel or tobacco distributor," "bulk filer of city withholding," "sales and use tax only." Use the words people use on their own forms.
2. Give each group one row. Where they go after the date, what's different, whether their login carries over, and the one thing they should do before the switch.
3. Name the people who don't move. Say plainly that sales, use and withholding filers stay in MTO. That sentence will save a lot of calls.
4. Handle the mixed cases. Someone with taxes in both places needs to be told that's expected, not an error.
5. Put closure dates next to the groups they affect. A business owner doesn't need individual income tax closures; a tax preparer needs all of them.
6. Keep it updated, and date the updates. Every change should carry a "last updated" line.

Test the page on people who weren't in the planning meetings. Hand it to someone at the front desk, give them three made-up callers ("I sell cannabis in Grand Rapids," "I do payroll for a Detroit restaurant," "I only file sales tax") and see whether they land on the right row in under a minute. If they hesitate, the reader will too.

The same structure works for a support team. Give call handlers the same sort, so the first question is "What do you file?" instead of "Which system are you in?"

After November 12

The first two weeks after a go-live are when you learn whether your sorting worked. For an agency, watch for three signals: people logging in to the wrong system, people asking whether their old payments carried over, and people who expected to move and didn't, or the reverse. Each is a sign that a group's row on the which-door page needs better words.

For filers, check that any payment you made before the switch shows correctly once systems resume, and keep confirmation numbers until it does.

We've also written about what happens to closed tasks and history when a portal switches, which is the next question most people ask after "where do I go?"

If you're planning a phased migration for a public service and want help with the cutover plan and the pages that explain it, our government and public sector team does that work. Get in touch and tell us who moves and who stays.

Related work: Sutton Place.