Does the country determine the tax payment voucher number according to the taxpayer's ID number? Then what is the basis for determining the business license number? Answer: Code of tax registration certificate number: the coding rules of tax registration certificate number code of individual industrial and commercial households (without organization code certificate), which are generally personal ID number+area code letter+serial number. (Generally, it is 20 digits. Because of the old ID card, it may be 17 digits. ) The coding rules of the tax registration certificate number code of individual industrial and commercial households and enterprises that have already handled the organization code certificate are generally 6 digits +9 digits of the organization code certificate number. (No.:15th digit) Industrial and commercial business license: The coding rules of the new industrial and commercial business license are: 6-digit area code +2-digit economic property code +7-digit serial number.