Among others, the reform of the Family Code enabled an opportunity of derogation from the legal matrimonial property regime which has been of obligatory nature so far. Spouses can derogate from the legal matrimonial property regime by a contract on regulation of proprietary relations. Thus, the respect of the autonomy of the will of parties and dispositivity of a rule of law in the field of settling the property relationships between the spouses was introduced. Besides, the Slovenian legal system has recently adopted the Civil Union Act which enables the partners in a formal or an informal civil union the same rights in the property field as spouses and partners of informal relationships have. Up until now, partners from the informal civil union have not even been governed by law. By adopting the mentioned legislation, the positions of the Constitutional Court and the EU law to eliminate discrimination experienced by same-sex couples are thus respected. From now on, the spouses and the partners of informal relationship and the partners of the formal and informal civil union can draw on the resource of the autonomy in their property arrangement. In the process, they are limited only by regulations of constraint and public order and morality. To conclude this agreement, the form is prescribed, i.e. in a notarial record. Notaries will publish the so-called contracts on regulation of proprietary relations in the register of the contracts on regulation of proprietary relations. Thus, the effect of erga omnes will be established and the fulfilment of legal certainty will be pursued.