By Christopher Lutz (May 8, 2018, 2:26 PM EDT) -- Illinois has a relatively high corporate income tax rate compared to most states — a combined 9.5 percent — coming in at the fourth highest rate in the United States. In 2019, the governor's budget[1] anticipates that corporate and personal income taxes will constitute more than 50 percent of Illinois' general funds revenues, generating over $20 billion. Consequently, Illinois' administration of its corporate income tax generates a significant amount of litigation compared to many other states. While calculating Illinois base income is generally straightforward, certain aspects are rather complex, particularly with respect to foreign income and dividend income from certain types of investment companies....