Definition. A Single Window is a facility that allows parties involved in international trade and transport to lodge standardized information and documents with a single entry point to fulfil all import, export, and transit-related regulatory requirements. If information is electronic, then individual data elements should only be submitted once. Overview. Governments and trade have established an extensive range of agency-specific and country specific regulatory and operational requirements for international trade with little coordination amongst each other, either at the national or international level. As a result, traders are faced with a confusing set of duplicative and redundant reporting requirements, forms, systems, data sets, data models, and messages. Governments and trade have to develop and maintain different systems to meet these redundant and duplicative requirements. This adds enormous costs to all parties, both in terms of fiscal resources and timeliness and accuracy of data. This problem has become more acute in recent years with the requirements for faster information delivery, often in advance of shipping, for security and other purposes, and the expanding requirements of data harmonization in international supply chains. The ability to handle data efficiently and swiftly has, in fact, become a key element in international competitiveness, especially in international supply chains. A “Single Window” is designed to overcome this complex system of data submission and regulatory control. While the primary objective is the single submission of data, establishing a SW necessitates a major rationalization of the current approach and requirements, and especially the reuse (and elimination of duplication) of existing data wherever possible.