The National Single Shipping Box (SNS) is the information system in which information is submitted before ships dock in Greek ports or when they depart from them. The National Single Maritime Box is connected to other information systems, such as the SafeSeaNet maritime information exchange system, and is the place where information is declared once by the obligees and then made available electronically to the various competent national authorities and Member States.

The legal background for the implementation of the National Maritime Single Window is set by the directive 2010/65/EU of the European Parliament and of the Council, regarding the formalities for submitting declarations for ships when they arrive and/or depart from ports of the Member States and for the repeal of Directive 2002/6/EC. This directive was incorporated into national law with PD 125/2012.

The project through which the National Single Maritime Portal was developed was included in the priority axis "Promoting the implementation of the Integrated Maritime Policy" of the Operational Program "Fisheries and the Sea 2014-2020", which is co-financed by the European Fisheries and Maritime Fund. The Maritime Safety Directorate is designated as an urgent Directorate of the Headquarters of the Coast Guard - Hellenic Coast Guard for the Development and Implementation of the National Single Maritime Mailbox.

Consequently, the proposal is assessed as partially implemented, until its extension and the application of the acceleration of VAT refunds.