International Convention on the Harmonization of Frontier Controls of Goods
In order to facilitate the international movement of goods, this Convention aims to reduce the need to complete formalities, as well as the number and duration of controls, notably through the national and international coordination of control procedures and their application.
The convention seeks to streamline administrative procedures and remove cross-border technical barriers. The convention applies to all goods being imported or exported or in transit, when they are moved across one or more sea, air or inland frontiers.
Provisions relevant to the cross-border paperless trade: Article 8 also mentions that the Contracting Parties shall endeavor to reduce paper documents and to simplify documentation procedures by using electronic systems for the exchange of information.
Text and amendments: https://treaties.un.org/pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XI-A-17&chapter=11&clang=_en