The validity of contracts signed without full knowledge or in a state of ignorance regarding their terms is a significant issue in both Ja‘fari Fiqh and Iranian law. This study examines the validity of signature-based contracts under such circumstances and provides a comparative analysis. The research adopts a descriptive-analytical approach, relying on library studies of jurisprudential and legal sources as well as practical examples, such as banking contracts. Findings indicate that in Ja‘fari Fiqh, a contract’s validity requires genuine intent and detailed awareness of its terms; signing without such knowledge and intent renders the contract invalid. In contrast, Iranian law considers a signature sufficient as evidence of consent, making the contract legally binding. To reconcile jurisprudential principles with legal practice and ensure transaction validity, four key measures are recommended: (1) emphasizing parties’ responsibility to review and understand contract terms, (2) providing clear explanations of contract contents before signing, (3) promoting public awareness and decision-making capacity, and (4) employing supportive tools such as simplified sample contracts or digital platforms to ensure informed consent. Implementing these measures can help reduce conflicts between religious and legal standards while enhancing transparency and legitimacy in daily transactions.