Yes When buying gold bars, we usually provide proof of purchase. When buying gold bars from the bank, the bank will issue us an invoice, which has detailed records, such as when to buy, the grams of gold bars, the unit price and purity purchased at that time. Because valuables such as gold are recycled by banks or gold shops, it is necessary to issue proof of the source of gold bars. The invoice or receipt when purchasing the gold coupon is one of the most important evidences. For the bank, if there is no invoice, these gold bars will be rejected, because without an invoice, it cannot be proved that these gold bars were purchased from him or that you obtained them through normal channels. Once these gold bars of unknown origin are taken away, if something happens, then the bank has the responsibility to get away. Gold bars are investment varieties in the gold market, which are mainly divided into physical gold investment and gold investment derivatives derived from physical gold. Derivatives mainly include gold futures and gold options, and physical gold investment mainly includes gold bars, coins and gold ornaments.