Even as there are several Single Window initiatives taking shape all over the world, there are no clear standards or guidelines concerning this area. Customs is increasingly being expected to participate in and take responsibility for Single Window implementations.
The document “Single Window: Implications for Customs Administrations” [ru] describes the possible impact that developments around a Single Window Environment has on the future of Customs' Business.
WCO has developed Single Window Data Harmonization Guidelines [ru] to provide Single Window environment developers with tools that can be used in order to achieve data harmonization and to develop internationally standardized data sets including the data element names, definitions, the United Nations Trade Data Element Directory (UNTDED) tag and the formats.
To support capacity building efforts, the WCO has developed a Compendium on “How to Build a Single Window Environment”. The Compendium comes in two volumes. Volume 1 [ru], called the ‘Executive Guide’, deals with aspects of Single Window that are of concern to senior management. Volume 2 [ru] is called the Professional Practice Guide and is a collection of tools and techniques to support technical experts working on projects to establish a Single Window.
"A Supplement Edition to the WCO Single Window Compendium" On How to build a Single Window Environment" was developed in 2015. The Supplement provides a succinct approach to the Single Window concept, which would be useful to Members and other stakeholders in the implementation/enhancement of Single Window environment. It would serve as a supplementary training package for national and regional Technical Assistance and Capacity Building activities".
The United Nations Centre for Trade Facilitation and Electronic Business (UNCEFACT) has developed Recommendation 33 [ru] on the subject, which is an important piece of work in this area.