Squire Patton Boggs’ Jeff VanderWolk, addresses how Reuven Avi-Yonah’s recent letter to the editor maintains that customary international tax law (CITL) is dynamic, changing to reflect the “general and consistent practice of states.”1 I am happy to say that I fully agree with him on that point, and I thank him for his kind words about my earlier letter2 arguing that the UTPR (now known as the undertaxed profits rule) is inconsistent with CITL.
In order for the UTPR to become part of CITL, it seems necessary for it to become a general and consistent practice of states through actual implementation of the model rules in the domestic laws and administrative practices of a sufficiently large number of countries. Maybe that will
happen, but it certainly hasn’t happened yet.
*This article was first published in Tax Notes on November 28, 2022.