Import and export commodities customs tax number based on the "Customs Code Table".
"Customs Code Table" in the corresponding customs code, the fifth to eight for the customs acceptance of the calendar year, the ninth for the import and export signs ("1" for import, "0" for export), the last 9 bits for the sequential number.
The following is the customs declaration customs numbering rules related to the introduction:
The customs declaration customs number for the 9-digit number, of which 1-2 for the acceptance of the declaration of the Customs No. (the "Customs Code Table" in the corresponding Customs Code of the last 2), the third for the Customs acceptance of the declaration of the calendar year of the last 4-digit number of the last bit, after the last 6-bit number for the sequence of numbering.
Import declarations and export declarations should be numbered separately to ensure that in the same calendar year, can be imported and exported uniquely identify each of the Customs declaration of this customs area digital.
The customs declaration customs number for the 18-digit number, of which bits 1-4 for the acceptance of the declaration of the customs number (the "Customs Code Table" in the corresponding customs code), bits 5-8 for the Customs acceptance of the declaration of the calendar year, the ninth for the import and export signs ("1" for import, "1" for export). "for import," "0" for export), the last nine for the sequential number.
The above information refers to Baidu Encyclopedia - Customs Numbering