Exercise of joint parental authority: In the case of the adoptive parent married to the minor's biological father or mother

Abstract

This article ain to examines the joint exercise of parental authority by adoptive parents and birth parents under Thai law and comparative foreign legal systems, with a view to proposing legislative reforms that would enable the shared exercise of such authority where the adoptive parent and a birth parent are spouses. Employing a documentary research methodology, the study analyzes statutory provisions alongside comparative doctrines and principles from selected jurisdictions. Although adoption is not, in itself, a ground that extinguishes the relationship between the child and the child’s birth parents, the legal effect of adopting a minor in practice transfers parental authority over the minor entirely to the adoptive parent. This absolute transfer effectively displaces the natural and legally recognized authority of the birth parents and gives rise to incoherence in the allocation and exercise of parental powers between adoptive parents and birth parents—particularly in cases where the parties are married to each other. The study highlights these doctrinal tensions and uses comparative insights to formulate recommendations for clarifying and restructuring the legal framework governing shared parental authority in such family constellations. The study finds that while jurisdictions vary, a common guiding principle is the best interests of the child. Canada, in particular, provides that when an adoptive parent and a birth parent are married to each other, they automatically share parental authority to safeguard the child’ s welfare in line with the Convention on the Rights of the Child. To enhance legal clarity and reduce interpretive disputes, this article proposes amending the Thai Civil and Commercial Code to recognize joint parental authority where the adoptive parent is the spouse of a birth parent who already exercises parental powers— without extinguishing the birth parent’ s authority, unless a court determines that joint authority would not serve the minor’ s best interests. Such a reform would promote family stability, protect children’ s rights, and strengthen the Thai family institution.