United Nations Centre for Trade Facilitation and Electronic Business (UN/CEFACT) Recommendation Number 33 enables the establishment of the single window system, whereby trade-related information and/or documents may only be submitted once at a single point using the modern information technologies to fulfil all import, export, and transit-related requirements, central control and central payment procedures for the entire customs duties, taxes and fees. The Single Window issue is also regulated in Article 10.4 of the Trade Facilitation Agreement agreed by the General Council of the World Trade Organization but it is not in effect yet. The aim of the single window system is to enable the submission of an application and the reception of a reply at a single point for those declarant who are in need of permit and approval from public enterprises for import and export operations.
The system also enables the transfer of relevant information to electronic media, thus allowing the declarants to submit their application documents at one point. In the case that the application results are affirmative, the documents may be shared between the parties involved in foreign trade transaction. Hence, the declarants are obligated to submit their documents repeatedly, thus contributing to saving time and cost.