<![CDATA[Child adoption is a common legal phenomenon in Indonesia intended to fulfill family psychological needs and child welfare. However, the absence of explicit regulations regarding the legal consequences of inheritance in Government Regulation No. 54 of 2007 often triggers civil disputes, particularly from an Islamic law perspective. Objective This study aims to analyze the legal standing of adopted children in Islamic inheritance distribution and examine the legal consequences of notarial procedural malpractice in issuing inheritance certificates based on Decision Number 4309/Pdt.G/2025/PA.Tgrs. Methods The research method used is normative juridical with a case and statutory approach. Secondary data were analyzed qualitatively using a deductive method. Results The results indicate that according to the Compilation of Islamic Law (KHI), adopted children do not have a lineage (nasab) relationship and thus are not entitled to be legal heirs; instead, they are entitled to a mandatory will (wasiat wajibah) of a maximum of 1/3 of the estate. Decision Number 4309/Pdt.G/2025/PA.Tgrs reveals that including an adopted child as a biological heir and ignoring a legitimate heir (the biological mother) in a notarial deed constitutes a substantive defect. Furthermore, violations of the procedure stipulated in Article 16 paragraph (1) letter m of the Notary Position Act result in the deed losing its authenticity. Conclusion This study recommends strengthening lineage verification by notaries and the need for synchronized regulations regarding the inheritance consequences for adopted children in Indonesian positive law to ensure legal certainty.]]>
