According to Baidu Encyclopedia, the invoice has a bottom ticket, and the bottom ticket of the invoice is the invoice stub. When the invoice is lost or invoiced, it will be reimbursed and collected by the customer. The bottom ticket can be used as the bottom ticket, and it can also have legal effect.
The difference between the whole ticket and the bottom ticket is that the whole ticket is an invoice with sufficient amount according to the actual amount, and the bottom ticket is an invoice stub.