Zawarcie umowy o podział quoad usum w sposób dorozumiany a sto-sowanie art. 207 k.c.

The subject of the article is the impact of the Supreme Court’s jurisprudence on the shaping of rights and obligations of co-owners in joint-ownership within an implied quoad usum agreement. The Supreme Court’s argumentation will be discussed, according to which an alteration of the sta-tutory regime of joint possession, if performed by the co-owners, entails modification of rights and obligations of the parties in terms of bearing burdens and deriving benefits from the property. Therefore, a question arises concerning the theoretical classification of the reasoning of the Su-preme Court. The purpose of the article is to demonstrate that the legal reasoning applied by the Supreme Court is based on two pre-sumptions, whereby the first refers to the potential will of co-owners, and the second is limiting it. Moreover, both structurally and functionally, this reasoning has similar characteristics to legal fiction.