There are obvious differences between the quality guarantee of gold jewelry and the invoice in function and function. Warranty is mainly used to ensure product quality and provide after-sales service, and invoice is a formal voucher for purchasing goods or services, which can be used to confirm the information such as the transaction party and transaction amount, and has important tax functions.

In short, the quality guarantee is the proof of the merchant's commitment to the quality of the goods sold, and the invoice is the official certificate of purchasing the goods or services.