The Illinois Dept. of Revenue adopted an emergency regulation that explains the requirements for “Wayfair nexus” after the recent U.S. Supreme Court case. IL has enacted nearly identical selling thresholds as those in the Wayfair case. They require retailers with no physical presence in IL to collect and remit use tax beginning 10/1/18 if the cumulative gross receipts from tangible personal property sales to purchasers in IL are $100,000 or more, or the retailer enters into 200 or more separate transactions for such sales.