Executive summaryOn 6 April 2021, the Spanish Government approved the Regulations setting forth Spanish Mandatory Disclosure Rules (MDR). The Regulations were published in the State Official Gazette on 7 April 2021 and enter into force on 8 April 2021, and are effective as from that same date.The final Spanish MDR Regulations are generally aligned to the requirements of the European Union (EU) Directive on the mandatory disclosure and exchange of cross-border tax arrangements.The key highlights of the Spanish MDR Regulations are summarized below.Detailed discussionBackgroundOn 31 December 2020, the Spanish legislation to implement the EU Directive on the mandatory disclosure and exchange of cross-border tax...