On November 26, 2018, the MTC filed an amicus brief in the Utah Supreme Court on behalf of the Utah Tax Commission in Steiner v. Utah Tax Commission. In its brief, the MTC explained that Utah’s individual income tax comports with both the dormant interstate Commerce Clause and the dormant foreign Commerce Clause of the U.S. Constitution, notwithstanding the fact that Utah’s tax does not allow its residents to apportion their income and does not provide a credit for national and substantial taxes their residents pay to foreign jurisdictions. Utah generally taxes 100% of residents’ income and provides a credit for taxes paid to other U.S. states. Virtually all state broad-based individual income taxes around the country are structured in relevant respects like the Utah tax.
You can read the brief by clicking here 