Executive summaryOn 14 October 2020, the Luxembourg Tax Authorities (LTA) released the Mandatory Disclosure Rules (MDR) XML schema and User Guide on submitting MDR reports. Such reports are required under the implementation of 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 file information on reportable cross-border 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 24 July 2020, the deadline for the filing and exchange of...