Some of the largest arbitral awards rendered in favour of investors have been based on tax-related (mis)conduct of host states towards investors, e.g., a series of Yukos and others v Russia – US$ 50 billion (the largest award ever rendered), Occidental v Ecuador (II) – US$ 1.77 billion, Cairn v India – excess of US$…

In 2015, Ecuador changed its General Organic Code of Processes (procedural law or COGEP) and imposed an exequatur procedure for foreign awards. The Law of Productive Development, Attraction of Investment, Employment Generation and Tax Stability (Investment Law) enacted in 2018 repealed this requirement. Nevertheless, despite this amendment, there are still practical difficulties that parties face…