Michigan Compiled Laws, Chapter 141. Municipal Financing § 141.646

Sec. 46.  An amended return shall be filed with the city or the department, on a form obtainable from the city or the department, if necessary to report additional income and pay an additional tax due, or to claim a refund of tax overpaid.  Within 90 days after final determination of a federal tax liability that also affects the computation of a taxpayer's city income tax liability, the taxpayer shall prepare and file with the city or the department an amended city income tax return showing income subject to the city tax based upon the final determination of federal income tax liability, and pay any additional tax shown due on the return or make a claim for refund of an overpayment.  A taxpayer shall not change the method of accounting or apportionment of net profits after the due date for filing the original return or any extensions for the filing of the original return.