The Bank of China will face a daily fine in the US unless it complies with a court request to give details of customers accused of selling fake goods.
The bank was held in contempt of court in Manhattan last week for refusing to turn over the records.
The state-owned lender is appealing the civil contempt order and fine of $50,000 a day starting on 8 December.
It said it would be violating China’s privacy law if it gave the information.
The records stem from a 2010 lawsuit by a group of luxury retailers including Gucci and Yves Saint Laurent that sued a group of Chinese companies for allegedly selling counterfeits goods like handbags.
The luxury brands had asked US district judge Richard Sullivan to order the Bank of China (BOC) to pay $12m (£8m) to cover their losses from counterfeiting or impose a fine.