Executive summaryThe Luxembourg Tax Authorities, on 13 May 2020, issued guidance (the Guidance) addressing the European Union (EU) Directive on the mandatory disclosure and exchange of cross-border tax arrangements (referred to as DAC6 or the Directive). Under DAC6, taxpayers and intermediaries are required to report cross-border reportable arrangements from 1 July 2020. However, reports will retrospectively cover arrangements where the first step is implemented between 25 June 2018 and 1 July 2020.On 17 February 2021, the Guidance was updated to address the impact of Brexit on the obligations under the Luxembourg implementation of DAC6 and to provide some guidance on the concept of...