Import identification number refers to a set of numbers or character combinations used to identify imported goods in international trade. Import identification number usually includes elements such as country code, importer code, port of shipment and cargo code. In the process of import, the accuracy of filling in the import identification number will directly affect the acceptance and release of customs, so enterprises need to fully understand the meaning of the number and fill in the specifications.

Import identification number has certain particularity for imported goods from different countries and industries. For example, the import identification number used in the United States is "customs goods code", Brazil is "import goods classification certificate number" and Chinese mainland is "customs number". In addition, different industries need different import identification numbers for imported goods. Therefore, when importing goods, enterprises need to fill in the correct import identification number according to the importing country and the type of goods.

As an important measure to protect national economic security and consumers' rights and interests, many countries require that imported goods must go through formal trade procedures and obtain effective import identification numbers. Import identification number can be used as evidence of international trade disputes and legal disputes, which is helpful for all parties to strengthen cooperation and trust and promote the stability and development of international trade.