UK has put forth new legislation, commencing 1/1/2021, focusing on Hallmark D only while they are presumably modifying the EU rules to new UK rules.
As an update, HMRC has clarified that only Hallmark D arrangements, including historical arrangements, are required to be reported commencing 1/1/2021.
Several Member States have started to issue additional guidance, as they prepare for implementation. The UK and Dutch administrations have issued new guidance, although they have both adopted the 6-month reporting deferral.
Examples in both sets of guidance are informative, and may also serve as a trend for other Member States that are in the process of implementation.
However, Germany, among others, remains fairly silent in this guidance as they have not adopted the deferral period, with reporting deadlines at the end of July and August 2020.