<![CDATA[The purpose of this study is to analyze the legal position of private land sale and purchase agreements as a source of potential land disputes and to formulate the preventive role of notaries and land deed officials in the framework of dispute prevention from the pre-transaction stage. This research is motivated by the prevalence of private land sale and purchase practices, which reveal a fundamental conceptual problem in the form of disharmony between civil law, which emphasizes the validity of agreements based on the agreement of the parties, and agrarian law, which requires formalization and registration as a condition of legal certainty. This lack of synchronization results in a dualism of legitimacy that weakens legal protection and increases the potential for disputes. This study uses a normative juridical method with a regulatory and conceptual approach, using the theoretical framework of preventive legal protection and legal system theory. The results of the study show that under-the-table land sale and purchase agreements, although valid under civil law, are not integrated into the land administration system, thus creating structural vulnerabilities in legal certainty and protection of rights, including those of third parties. This study concludes that the prevention of land disputes requires institutional intervention from the pre-transaction stage through legal verification mechanisms, gradual formalization of rights transfers, and legal education. The novelty of this research lies in the development of a structured preventive model as a theoretical contribution to strengthening the concept of preventive legal protection in land law, as well as a systemic critique of the lack of synchronization between civil validity and administrative recognition in the Indonesian land law system. Tujuan penelitian ini adalah menganalisis kedudukan yuridis perjanjian jual beli tanah di bawah tangan sebagai sumber potensi sengketa pertanahan serta merumuskan peran preventif Notaris dan Pejabat Pembuat Akta Tanah dalam kerangka pencegahan sengketa sejak tahap pra-transaksi. Penelitian ini dilatarbelakangi oleh masih maraknya praktik jual beli tanah di bawah tangan yang menunjukkan adanya problem konseptual mendasar berupa disharmoni antara hukum perdata yang menekankan keabsahan perjanjian berdasarkan kesepakatan para pihak dan hukum agraria yang menuntut formalisasi serta pendaftaran sebagai syarat kepastian hukum. Ketidaksinkronan tersebut menghasilkan dualisme legitimasi yang melemahkan perlindungan hukum dan meningkatkan potensi sengketa. Penelitian ini menggunakan metode yuridis normatif dengan pendekatan peraturan perundang-undangan dan konseptual, dengan kerangka teori perlindungan hukum preventif serta teori sistem hukum. Hasil penelitian menunjukkan bahwa perjanjian jual beli tanah di bawah tangan, meskipun sah secara keperdataan, tidak terintegrasi dalam sistem administrasi pertanahan, sehingga menimbulkan kerentanan struktural dalam kepastian hukum dan perlindungan hak, termasuk terhadap pihak ketiga. Penelitian ini menyimpulkan bahwa pencegahan sengketa pertanahan memerlukan intervensi kelembagaan sejak tahap pra-transaksi melalui mekanisme verifikasi yuridis, formalisasi bertahap peralihan hak, dan edukasi hukum. Kebaruan penelitian ini terletak pada pengembangan model preventif terstruktur sebagai kontribusi teoritis terhadap penguatan konsep perlindungan hukum preventif dalam hukum pertanahan, sekaligus kritik sistemik terhadap ketidaksinkronan antara validitas perdata dan pengakuan administratif dalam sistem hukum pertanahan Indonesia.]]>
