This paper will present the legal property system applying to spouses in the absence of a marriage agreement between them. In accordance with the legal property system, spouses may own their own property and matrimonial property. Matrimonial property is property that spouses have acquired through work or that derives from property acquired through work during the marriage. Matrimonial property is actually co-ownership, and this paper will present the manner in which it is managed. The second part of the paper is dedicated to immovable property that represents matrimonial property and should be registered in the land register as co-owned by the spouses. In the absence of registration, the possibility opens for the registered spouse to dispose of the immovable property without the consent of the other spouse. In this situation, there is a conflict of two legal principles. The first principle is Nemo plus iuris ad alium transferre potest quam ipse habet, according to which no one can transfer more rights to another than they themselves own. In these situations, it comes into conflict with the second principle, which is the principle of trust in the land register, which protects an honest third party who did not know or had no reason to suspect that the situation in the land register is incomplete and that the registered spouse is not the sole owner of the immovable property. Court practice has long been inconsistent on this issue, and the paper presents the positions taken by courts in their decisions. The conclusion provides a review of the conflict between the two legal principles and the court practice.