The Michigan Supreme Court heard oral arguments today in the case of IBM v. the Michigan Department of Treasury. At issue in the case are IBM’s 2008 Michigan tax returns. IBM, using a formula set forth in the Multi-State Tax Compact, which Michigan joined in 1969, calculated the company was entitled to a tax return of approximately 6 million dollars. The Dept. of Treasury, using a conflicting formula contained in the Michigan Business Act, determined IBM was only entitled to a refund of approximately 1.3 million. Two separate lower court rulings sided with the Dept. of Treasury, finding that IBM was required to use the formula established by the Michigan Business Act. That finding eventually led IMB to appeal the ruling, setting the stage for today’s argument.