Today, various legal systems seek effective solutions to address theoretical and practical gaps in contract and property registration law. A major challenge in this field is the conflict between private (ordinary) and official documents, which has led to scholarly disagreements and inconsistent court rulings across jurisdictions. One of the most effective mechanisms to address this conflict is the principle of good faith. This study examines the role of good faith in the U.S. property registration system and evaluates how it can be applied to resolve existing issues within the Iranian legal framework. After defining the concept, the article analyzes the operational structure of good faith in the U.S. system and assesses its compatibility with Iranian property law, particularly the law requiring the official registration of immovable property transactions. The findings suggest that incorporating good faith principles into Iranian law aligned with current property registration rules can strengthen protections for third parties acting in good faith. This alignment would also help unify judicial practice and reduce scholarly and judicial conflicts, while addressing long-standing deficiencies in Iran’s registration system. Adopting such a framework can offer a more coherent legal approach to property transactions and promote greater legal certainty.