Customer tax number refers to the identification code of the taxpayer enterprise. The identification code of each enterprise is unique, equivalent to the "identity card" of the enterprise. According to the notice No. 56 of the General Administration of Customs of China in 2018 on the adjustment of the regulatory matters of the import and export manifest, the manifest requires that details of the receipt, consignor and notifier (if indicative bill of lading) be filled in during the filing process, such as the unified Social Credit Code or the Organization Code and its contact information provided by enterprises in China. Foreign companies are required to fill in the "code abbreviations and enterprise codes". In 2018, the General Administration of Customs issued the Enterprise Code Type Summary for enterprise reference, including the code table of countries around the world, as well as a comparison table of Chinese enterprise registration types. Enterprise code declarations can be completed based on the index of the country or region in the table. Fill in the format as "Code Abbreviations and Enterprise Codes". If the country or region does not appear in the Enterprise Code Type Summary Form or cannot provide the type of enterprise code listed in the form, it shall fill in the legal enterprise registration code of the actual consignee and the notified person in the country or region in which it is located, and fill in the form of "9999 plus enterprise code"; for natural persons, they should fill in their id card, passport number or other valid documents in the form of "ID and ID number", "PASSPORT and passport number" and "8888 plus identity code". As for business code types, such as Company Number or VAT Number signed by UK registered businesses, Central Index Key for US registered businesses, EIN Enterprises, Legal Entity Identifier, etc.