kāi / diàn / zǐ / fā / piào / shí / xì / tǒng / huì / yāo / qiú / shū / rù / tǒng / yī / biān / hào开电子发票时,系统会要求输入统一编号。When issuing an electronic invoice, the system will ask you to enter the VAT identification number.