EN
The aim of this paper is to define the terms of 'business activity (commercial activity)' and 'professional activity' as stated in Article 43' of the Civil Code. Both terms are crucial in defining the concept of entrepreneur in the view of the Civil Code. The definition of neither of the terms can be found in the legal act. Thus, the author is attempting to define the scope of their meaning, taking into consideration the purpose for which they were introduced. In author's own opinion, the hitherto prevailing practice of interpreting the meaning of the analysed terms on the basis of legal acts of the public law is inappropriate. He also presents his critical approach to the existing doctrine and jurisdiction, especially this of the Supreme Court. Concurring with the opinion that both 'business activity' and 'professional activity' have autonomous meanings in the view of the Civil Code, the author proposes his own definition of the above mentioned terms. In doing so, he considers the following factors: (i) performing a 'business activity' or 'professional activity' belongs to the sphere of facts independent of fulfilling any formal conditions, (ii) basis for forming definitions of the above mentioned terms should be verifiable in a way that is at least objective, (iii) when defining the terms of 'business activity' and 'professional activity' one should consider the necessity of legal protection of the contracting party that deals with either type of the transactor party. According to the proposition presented in this paper, 'a business activity' should be interpreted as 'participation in the market in such a way that one is convinced that one has to do with an independent company whose aim is to make profit from its commercial activity'. On the other hand, by 'professional activity' the author understands 'performing a profession which has the characteristics of a non-business (non-commercial) activity that has to be done in person and requires certain qualifications from the service provider'.