The high validity of informal (ordinary) transactions of immovable property in Iran is one of the primary roots of land grabbing, conflicting transactions, and a large portion of the judicial and criminal claims in the judiciary, given that a significant portion of ownership remains officially unregistered and its transfer occurs outside governmental oversight. This situation, in addition to undermining property rights security and causing stagnation in the business environment, increases the likelihood of fraud—such as selling another's property and reselling a single property to multiple individuals—and strengthens the economic incentives for land grabbers. The central issue in the weak registration system is the lack of effective enforcement mechanisms to mandate the formal registration of transactions and an excessive commitment to freedom of will in property transfers, without regard for public interests and governmental policymaking tools. The corrective strategy emphasizes reviewing the "effects of registration" and strengthening two fundamental principles of global registration systems: the mirror principle (reflecting all rights and interests in registration books) and the curtain principle (protecting the current registered owner from flaws in the past chain of ownership). Three policy models are proposed to invalidate informal transactions: transaction nullity, non-transferability of ownership, or non-enforceability against third parties. Furthermore, designing a rapid and low-cost transition period for registering acquired rights and reducing judicial cases, along with establishing compensation funds for victims acting in good faith, is introduced as a prerequisite for the successful implementation of reforms.