General administration of customs base. Customs Training According to the inquiries from official website, People's Republic of China (PRC) and the General Administration of Customs, we know that we are going to the General Administration of Customs base to understand the training content and explore the training base. Customs is an administrative agency established by a country at coastal, border or inland ports to implement import and export supervision. Supervise and inspect inbound and outbound postal articles, goods, passengers' luggage, currency, gold and silver, securities and means of transport, collect customs duties, and carry out tasks such as banning smuggling.