The formal registration of real estate transactions is a crucial legal instrument for ensuring property security, reducing property-related litigation, protecting third parties, and guaranteeing transparency in the circulation of wealth. In Iranian law, despite the long-standing existence of the land and deed registration system, a significant conflict has persisted between the validity of "ordinary documents" (unregistered private contracts) and the necessity of formally registering real estate transactions. While the recognition of ordinary documents in certain judicial practices upholds the parties' intent and the principle of the validity of contracts, it has simultaneously paved the way for conflicting documents, competing transactions, land grabbing, protracted litigation, and property ownership instability. In contrast, the English land registration system is founded on the registration of title and the clarification of the legal status of properties; it seeks—through the registration process—to make ownership and land-related rights enforceable against third parties. In this system, land registration is not merely an administrative formality but a substantive mechanism for securing ownership and fostering public trust in registration data. Employing a descriptive-analytical method and a comparative approach, this study compares the requirement for the formal registration of real estate transactions in Iranian law with the land registration system in England. The findings indicate that the efficiency of a registration system depends on legislative clarity, the validation of registration data, the limitation of the legal effects of ordinary documents, controlled public access to ownership information, and the provision of effective enforcement mechanisms. Consequently, the reform of Iran's registration system should aim to strengthen formal registration, curtail the validity of ordinary documents vis-à-vis third parties, and establish a comprehensive, reliable ownership database.