The land is one of the vital objects required to actualize development. The government that has the role of managing lands is obliged to provide lands for public interest development. Land supply does not change and affects the public land taking and authorization. The study’s problem was whether customary land right authorization for public interest development is an unlawful act if the landowner proposes a lawsuit after the authorization lasts for 46 years (expired). Within this period, the landowner is considered relinquishing the right or rechtsverwerking. This study aims to analyze customary land right authorization based on Article 1365 Indonesian Civil Code as well as to analyze whether the Judge's consideration is in accordance with the existing provisions so that in the end it can reflect legal protection and certainty regarding authorization disputes over customary land rights. The method used in the study was a normative judicial method based on the legislation. Customary law does not recognize an expiry date, and hence, problems regarding customary lands can be sued without a time limit if the ownership is proven. Customary law only recognizes rechtsverwerking, or the past time as the cause of losing land rights, if the right holder has not cultivated the land for a long time. Landowner never relinquished their right because the land was utilized for a school, and they paid taxes. The Jakarta Provincial Government authorized the land and changed the school building structure to become a more permanent building without the landowner’s permission and agreement. Therefore, it can be concluded that the customary law authorization was an unlawful act causing losses where the landowner could not authorize and utilize the land.