On September 17th, 2015, the U.S. Treasury Department and Internal Revenue Service (IRS) have released final and temporary regulations under Internal Revenue Code sec 871(m). Starting as of January 1st, 2017, these regulations, as Norbert Bramerdorfer and Dominik Stundner show, impose a framework to withholding agents world-wide for testing the “delta” of notional principal contracts (NPCs) and equity-linked instruments (ELIs) in referencing U.S. equities to determine whether such contracts are subject to U.S. withholding tax on dividend equivalent payments.