Penelitian ini bertujuan untuk menganalisis kekuatan dan akibat hukum surat kuasa pengurusan surat kepemilikan tanah pada harta warisan yang dibuat oleh seorang ahli waris tanpa persetujuan ahli waris lainnya, dengan kajian terhadap putusan pengadilan negeri kota tarakan nomor: 10/pdt.g/2023/pn tar dan putusan pengadilan tinggi kalimantan utara nomor: 23/pdt/2023/pt tjs. penelitian ini menggunakan metode penelitian hukum normatif dengan pendekatan peraturan perundang-undangan dan konseptual, serta mengacu pada bahan hukum primer, sekunder, dan non-hukum. hasil penelitian menunjukkan bahwa surat kuasa umum dapat digunakan untuk mengurus harta kekayaan pemberi kuasa. oleh karena itu, surat kepemilikan tanah sebagai salah satu bentuk harta kekayaan dalam warisan, dapat menjadi objek dari pemberian kuasa melalui surat kuasa umum sesuai dengan pasal 1796 kitab undang-undang hukum perdata. namun, surat kuasa pengurusan surat kepemilikan tanah pada harta warisan yang tidak dilengkapi dengan tanda tangan persetujuan dari ahli waris lainnya adalah tidak sah dan tidak memiliki kekuatan hukum serta melanggar prinsip hak setara atas warisan. ahli waris yang dirugikan memiliki perlindungan hukum melalui hak saisine dan hereditatis petitio untuk mempertahankan hak mereka. surat kuasa pengurusan surat kepemilikan tanah pada harta warisan yang dibuat oleh seorang ahli waris harus memenuhi syarat sah perjanjian, seperti identitas pemberi kuasa (seluruh ahli waris) dan penerima kuasa yang jelas, objek kuasa harus dijelaskan rinci, uraian/maksud pemberian kuasa harus tegas dan limitatif agar penerima kuasa tidak bertindak di luar wewenang. surat kuasa harus ditandatangani oleh pemberi kuasa (seluruh ahli waris) dan penerima kuasa serta dilengkapi materai. akibat hukum dari tidak memenuhi persyaratan tersebut, maka surat kuasa yang digunakan ialah batal demi hukum. surat kuasa pengurusan surat kepemilikan tanah pada harta warisan harus memenuhi syarat formal, menegaskan pentingnya persetujuan seluruh ahli waris dan kepatuhan hukum. kata kunci: surat kuasa, kepemilikan tanah, harta warisan.

The purpose of the study was to analyse the strength and legal consequences of a power of attorney for managing land ownership certificates in inheritance made by an heir without the consent of other heirs, by studying the decision of the tarakan city district court number: 10/pdt.g/2023/pn tar and the decision of the north kalimantan high court number: 23/pdt/2023/pt tjs. this study employed a normative legal research method with a statutory and conceptual regulatory approach, and refers to primary, secondary, and non-legal legal materials. the results of the study showed that a general power of attorney can be used to manage the assets of the grantor of power of attorney. therefore, a land ownership certificate as a form of asset in an inheritance can be the object of granting power of attorney through a general power of attorney in accordance with article 1796 of the civil code. however, a power of attorney for managing land ownership certificates in inheritance that was not accompanied by the signature of approval from other heirs was invalid and had no legal force and violated the principle of equal rights to inheritance. the injured heirs had legal protection through the right of saisine and hereditatis petitio to defend their rights. the power of attorney for managing land ownership certificates on inherited property made by an heir must meet the legal requirements of the agreement, such as the identity of the principal (all heirs) and the recipient of the power of attorney was clear, the object of the power of attorney must be explained in detail, the description/intent of granting the power of attorney must be clear and limited so that the recipient of the power of attorney did not act beyond their authority. the power of attorney must be signed by the principal (all heirs) and the recipient of the power of attorney and must be equipped with a stamp. the legal consequences of not meeting these requirements, then the power of attorney used was null and void. the power of attorney for managing land ownership certificates on inherited property must meet formal requirements, emphasizing the importance of the agreement of all heirs and compliance with the law. keywords: power of attorney, land ownership, inheritance.