%X The principle of protection and legal certainty in Indonesia is emphasized in Article 28D paragraph 1 of the 1945 Constitution which guarantees the rights of every person to recognition, guarantee, protection, and fair legal certainty, as well as equal treatment before the law. This study raises the issue of the application of interest based on an agreement in an agreement between the parties based on Article 1767 of the Civil Code which specifically examines the Decision of the Serang District Court Number 8/Pdt.Gs/2024/Pn.Srg by raising the identification of the problem of how the application of interest according to the agreement between the parties based on Article 1767 of the Civil Code in Court practice in Indonesia, and what is the basis for the Judge's legal considerations regarding the interest agreed upon by the parties based on Article 1767 of the Civil Code in the Decision of the Serang District Court Number 8/Pdt.Gs/2024/Pn.Srg. The method used is a normative legal research method that is descriptive analytical in nature. The results of the study show that the provisions on the amount of interest based on the agreement are still recognized in court decisions, then in practice it turns out that the amount of interest based on the agreement in the agreement is generally corrected by the judge based on the principles of appropriateness and justice. The basis for the judge's legal considerations regarding the interest agreed upon by the parties in the Serang District Court Decision Number 8 / Pdt.Gs / 2024 / Pn.Srg remains valid and recognized in practice. However, the judge's legal considerations that reduced the interest by 10% to 1% per month in his decision The judge was not able to provide strong legal reasons and considerations (onvoldoende gemotiveerd) so that the decision could not be maintained. This study suggests that the courts prepare and make clear and fair regulations regarding interest in agreements, and it is important for judges to include clear arguments to provide legal certainty. %O Prinsip perlindungan dan kepastian hukum di Indonesia ditegaskan dalam Pasal 28D ayat 1 UUD 1945 yang menjamin hak setiap orang atas pengakuan, jaminan, perlindungan, dan kepastian hukum yang adil, serta perlakuan yang sama di hadapan hukum. Penelitian ini mengangkat persoalan penerapan bunga berdasarkan kesepakatan dalam perjanjian para pihak berdasarkan pasal 1767 KUHPerdata yang secara khusus mengkaji tentang Putusan Pengadilan Negeri Serang Nomor 8/Pdt.Gs/2024/Pn.Srg dengan mengangkat identifikasi masalah bagaimana penerapan bunga menurut perjanjian para pihak berdasarkan Pasal 1767 KUHPerdata dalam praktik Pengadilan di Indonesia, dan bagaimana dasar pertimbangan hukum Hakim tentang bunga yang diperjanjikan para pihak berdasarkan Pasal 1767 KUHPerdata dalam Putusan Pengadilan Negeri Serang Nomor 8/Pdt.Gs/2024/Pn.Srg. Metode yang digunakan adalah metode penelitian yuridis normatif yang bersifat deskriptif analitis. Hasil penelitian menunjukkan bahwa ketentuan tentang besarnya bunga berdasarkan perjanjian tetap diakui di dalam putusan pengadilan, selanjutnya di dalam praktik ternyata besarnya bunga berdasarkan kesepakatan di dalam perjanjian pada umumnya hakim memberikan koreksi berdasarkan pada prinsip kepantasan dan keadilan. Dasar pertimbangan hukum hakim tentang bunga yang diperjanjikan para pihak dalam Putusan Pengadilan Negeri Serang Nomor 8/Pdt.Gs/2024/Pn.Srg tetap berlaku dan diakui dalam praktik. Namun pertimbangan hukum hakim yang menurunkan bunga sebesar 10% menjadi 1% per bulan dalam putusannya Hakim tidak cukup mampu memberikan alasan-alasan dan pertimbangan hukum yang kuat (onvoldoende gemotiveerd) sehingga berakibat pada tidak dapat dipertahankannya putusan tersebut. Penelitian ini menyarankan agar pengadilan menyusun dan membuat peraturan yang jelas dan adil mengenai bunga dalam perjanjian, serta hakim penting untuk mencantumkan argumentasi yang jelas untuk memberikan kepastian hukum. %T TINJAUAN YURIDIS PUTUSAN PENGADILAN NEGERI SERANG NOMOR 8/PDT.GS/2024/PN.SRG YANG MENGUBAH BUNGA KONVENSIONAL MENJADI BUNGA MORATOIR BERDASARKAN KETENTUAN PASAL 1767 KUHPerdata %L eprintuntirta50012 %A Istiqomatul Maulidah %I Universitas Sultan Ageng Tirtayasa %D 2025 %K Loan Agreement, Interest Agreement, Court Decision. Perjanjian Pinjam-Meminjam, Bunga Kesepakatan, Putusan Pengadilan