This research examines the application of law in a final and binding court decision regarding a buyback guarantee made by a housing developer because the debtor defaulted in a house sale and purchase transaction using a Home Ownership Credit (KPR) facility, reviewed from the Indonesian Civil Code (KUHPerdata). The research method employed is normative legal research with a statute approach, a conceptual approach, and a case approach. Based on the aforementioned, the research questions in this study are: 1) How is the practice of agreements with a buyback guarantee by housing developers towards consumers in the sale and purchase of houses using Home Ownership Credit (KPR) facilities?, 2) How is the agreement with a buyback guarantee in Civil Case Number 578 K/Pdt/2022 reviewed from the Indonesian Civil Code? The results of the discussion in this research, based on the research questions, are that the practice of buyback guarantee by housing developers in sale and purchase transactions using Home Ownership Credit (KPR) facilities must be interpreted as debt subrogation carried out in the event that the debtor has first committed a default. Regarding the application of legal regulations concerning buyback guarantee in Civil Case Number 578 K/Pdt/2022, the author opines that the judge's considerations were appropriate because they viewed the practice in the case at hand as debt subrogation.