The objective of this article is to analyse the concept of the legal professional privilege in the field of taxation. First, the Orde van de Vlaamse Balies case is examined in which the CJEU struck down an element of the mandatory disclosure regime contained in the fifth amendment to the Directive on Administrative Cooperation (DAC 6) as it was considered a disproportionate infringement of the legal professional privilege. The article challenges whether the CJEU was correct in simply further developing its own and the ECtHR’s precedence to reach the conclusion that all activities of lawyers as targeted by the DAC 6 fall within the scope of the strengthened protection of legal professional privilege. Additionally, it is concluded that the CJEU insufficiently took into account the DAC 6’s broader goals. Next, the article investigates ethical considerations concerning legal professional privilege, discussing particularly how it should be delineated in the field of taxation. The article concludes that the scope of legal professional privilege should not be expanded to include the activities of lawyers in tax planning.