Switch Bill of Lading, as one of the common yet sensitive practices in international maritime transport, refers to the process of replacing an original bill of lading with a new one in which essential details such as the name and address of the consignor and consignee, the place of origin or destination of the goods, and in some cases even the physical description of the cargo are altered. This practice is usually carried out in response to commercial necessities such as a change of buyer during transit, the need to issue documents that comply with the requirements of the final buyer, or, in more sensitive cases, to circumvent trade barriers, restrictive regulations, or international sanctions. Despite its significant role in facilitating international trade and providing flexibility in shipping operations, it should be noted that none of the major international regimes governing maritime transport of goods—including the various versions of the Hague Rules, the Hamburg Rules 1978, or the Rotterdam Rules 2008—explicitly and directly address the issue of switch bills of lading. Similarly, in the Iranian legal system, there are no specific and clear regulations that define this process and its legal consequences, which can lead to ambiguities and legal disputes among stakeholders. Within this context, the main question arises as to how the process of switching a bill of lading is actually conducted in practice, and what legal implications, restrictions, and challenges it entails. The present study, employing a descriptive-analytical method and relying on library research, analysis of relevant judicial precedents, and examination of related international instruments, seeks to answer these questions. The findings of the research indicate that although a switch bill of lading can be an effective tool for increasing flexibility in international transactions and adapting trade documents to the dynamic needs of commercial parties, its legal validity depends on compliance with essential conditions such as verifying the authority of the requesting party, ensuring the effective and complete cancellation of previous versions, and utilizing modern technologies such as electronic transport documents. Observing these requirements plays a crucial role in preventing fraud, minimizing legal disputes, and enhancing the security and transparency of shipping documentation in international maritime commerce.