Abstract: Private autonomy, freedom of contractual relationships, and the equality of participants are the basic principles of private law. Along with the development of an economic market, the need to protect the consumer as a“weak party” has increased. Very often costumers enter into a contract without considering the subject of the agreement or acquainting with another party. Moreover, consumers often receive contractual offers in unexpected environments. Thus are neither prepared nor ready to conclude an agreement immediately. Sellers often use pre-formatted terms and application without giving any additional warnings or explanations. Therefore, legal consequences of such contractual relationships are uncertain, unpredictable, and unexpected for consumers. Unlike entrepreneurs, consumers usually do not have the specifi c knowledge and experience that can be a prerequisite for concluding a reasonable and profi table agreement.