History of Nepal indicates the prevalence of customs since the Lichchavi era. Trade relation of Nepal was very limited before 1951. India and Tibet were the major trading partners. The task of customs revenue collection was given to the private sector on contract since the institutional base was weak and fragmented at that time. However the modern era of customs begins with the trade treaty with India in 1950. As a result, inner customs offices were closed and borders offices started to work as customs offices. After 1950, Tariff Board used to determine customs rates in accordance of which tariffs used to be levied. In 1956, all bazaar addas (border offices) were turned into customs offices. In 1957, Customs Commissioners' Office was established at the central level to look after customs related activities.