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For account specific questions, you will need to include the business's identification number and address as well as your relationship to the business. Additionally, if responding to a notice we sent to you, include the Letter ID printed at the top of page one.

Ask a Question

Access the eServices Business Tax Portal

eService Business Taxes is a portal where you can ask account specific or general questions that Treasury can reply to electronically. To submit a question, you will need details about the business and the Letter ID off any notice being referenced. Online responses to questions may take 7 business days to be available. If Treasury is unable to verify the information provided, the response will include a request to resubmit with updated information.

For additional resources and helpful information visit the Business Tax eServices Portal Help Center.

Update Account

Make updates to your account on Michigan Treasury Online

Log on to Michigan Treasury Online (MTO) to update business details, authorized representative information, and to file or pay tax returns.


Contact Michigan Treasury Online

Other ways to contact the Department of Treasury with questions about your business taxes.

Mail Us

P.O. Box 30427

Lansing, MI 48909

Call Us