The article contains a detailed commentary to the Ruling of the Plenum of the Supreme Court (SC) of Russia No. 18 «On Some Issues of Application of Customs Legislation by the Courts», 12 May 2016. The SC explained how courts should decide disputes concerning contesting the adjustment of the customs value and reclassification of goods by customs authorities, recovery of customs duties (including the case of the loss of temporarily imported vehicle). In addition, the Ruling provides some directions as to the allocation of the burden of proof. The SC introduces new criteria for admissibility of evidences in the court which were not submitted by the parties during customs inspection. The authors analyse all these issues and comment on the SC’s approach to the application of WTO and EAEC rules by courts. The paper compares SC’s position with previous judgments of the Supreme Arbitrazh Court and other courts and highlights new trends in court practice.