This article aims to examine the arguments and conclusions made by Advocate General Bobek in his Opinion delivered on 14 December 2017 in Hornbach-Baumarkt (C-382/16) and their potential consequences for taxpayers in EU Member States. In particular, it argues that cross-border situations targeted by the arm’s length principle (ALP) are comparable with purely domestic situations, which escape the burden of compliance with the ALP. The German transfer pricing rules may be considered disproportionate to the aim they pursue due to the limitation on a taxpayer’s rights to provide the commercial justifications for the transactions that do not comply with the ALP resulting from the parent company’s status as a shareholder.