Michigan Department of Treasury Confirms System Error Behind Recent Taxpayer Notices

By: Kelli Parker, Tax Associate  

If you’ve recently received a notice from the Michigan Department of Treasury, don’t panic. You’re not alone, and in most cases, no immediate action is required. 

Over the past week, the State of Michigan has issued a significant volume of notices to taxpayers as a result of a system error on Treasury’s end. The Department has acknowledged the issue and confirmed it is working to resolve it. 

What Happened?

The notices are largely tied to estimated payments and credit carryforwards that were not properly applied to taxpayer accounts due to the system error. Treasury has confirmed that all prepayments are accurately reflected in its eServices system – meaning your payments are on record. The notices themselves are incorrect. Corrected versions will be issued once the issue is fully resolved. 

Treasury believes the problem is limited to notices dated between March 30 and April 17, 2026, and has paused the issuance of additional notices in the interim. 

What Should You Do?

For most taxpayers, the answer right now is: nothing. Revised notices will be sent once Treasury confirms the system is functioning properly and all affected accounts have been identified. This is expected to happen before any appeal deadlines expire. 

If you receive a notice you disagree with and have not received a corrected version before your appeal rights expire, you should proceed with filing an appeal to protect your rights. 

Unexpected Refund Check? Do Not Cash It.

Some taxpayers may also receive refund checks from the State without any explanation. These may be related to Section 2210 underpayment penalties previously reported on returns. Treasury is advising CPAs to instruct clients not to cash these checks, as doing so could complicate the correction process. 

If you receive a refund check you believe was issued in error, return it uncashed to: 

Michigan Department of Treasury 
P.O. Box 30788 
Lansing, MI 48909 

Be sure to include a written explanation of why the check is being returned and keep a copy for your records. 

Have Questions? We’re Here to Help.

Navigating unexpected notices and unclear communications from the State can be stressful – but you don’t have to figure it out alone. If you’ve received a notice or a refund check and aren’t sure what to do next, the tax team at Maner Costerisan is ready to help you determine the right course of action. Contact us at 517-323-7500 or at maner@manercpa.com.