The concept of a consumer affects a number of issues of Polish and European law. The wide scope of this influence in practice means linking the “consumer” with a number of different normative contexts, which raises difficulties of interpretation. The question arises whether the legal assessments of a consumer developed on a given issue remain valid on another. A good example will be the “consumer” within the meaning of Regulation No 1215/2012. The understanding of that concept is characterized by a number of specific characteristics resulting from the autonomous (uniformed) interpretation of that regulation. The publication presents the basic assumptions of Regulation No 1215/2012 in more detail. An analysis of the Court of Justice of the EU (CJEU) jurisprudence has been carried out and the main interpretative directives used by the Tribunal have been identified, related in particular to the autonomous (uniformed) interpretation. Then, the understanding of the consumer from Regulation No 1215/2012 is presented, with particular emphasis on contentious issues, including mixed-purposes contracts.