According to the "Consumer Protection Law", Article 22 provides that: the operator to provide goods or services, should be in accordance with the relevant provisions of the state or commercial practice to the consumer to issue invoices and other purchase vouchers or service documents; consumer demand invoices and other purchase vouchers or service documents, the operator must be issued. The provisions of this article is the operator to issue proof of purchase or the obligation of service documents. Proof of purchase refers to the consumer from the operator to buy goods, the operator issued to the consumer to prove the purchase of the goods invoice or other shopping documents. The service document refers to the invoice or other written evidence obtained from the operator after the consumer receives the service from the operator.

The operator to provide goods and consumer services, should be in accordance with the relevant provisions of the state or commercial practice to the consumer issued proof of purchase and service documents; consumer demand for proof of purchase or service documents, the operator must be issued.