This study examines the decision of the Purwakarta District Court Number 37/Pdt.G/2023/PN Pwk concerning issues related to land sale transactions without an official deed, which give rise to default (breach of contract) and legal certainty regarding changes in land ownership status. The main issues in this study are how the legality of land sale transactions without an official deed is positioned under civil law and agrarian law perspectives, as well as how the law is applied in the court decision against the Defendant who failed to follow up on the agreement to execute the making of a Sale and Purchase Deed (AJB) before a Land Deed Official (PPAT). This study uses a normative juridical method with a qualitative approach supported by literature review and analysis of court decisions, statutory regulations, and relevant legal literature. Based on the findings, it is known that normatively, land sale and purchase transactions that are not embodied in an official deed may still give rise to civil legal relations if they fulfill the requirements for the validity of an agreement. However, the transfer of land rights must still be carried out through a deed made by a PPAT and registered at the Land Office in order to obtain strong legal certainty. In this case, the panel of judges recognized the validity of the sale and purchase agreement under the law and found that the Defendant had committed a breach of contract as a legal consequence of failing to perform the obligations under the agreement, particularly in attending the process of making the sale and purchase deed. However, the judge partially rejected the claim for compensation due to insufficient supporting evidence. This decision shows that legal protection for good-faith buyers is still provided through the court system, but formal procedures for transferring land rights must still be fulfilled in order to prevent similar disputes from recurring.