1. Credit cards (debit cards) have customer service numbers on their faces. You can call the customer service number on the card, and then you can manually check the bank of the credit card (debit card). If you don't want to make a phone call, you can also check the phone number on Baidu's credit card (debit card) online to see which bank it belongs to, so that you can also know the bank of the account.

2. Or pay attention to the official WeChat account of the bank. Generally, there will be a bank inquiry function. Take China Construction Bank as an example. Wechat "Customer Service of China Construction Bank", then send "Bank of Account" query on the page, click the pop-up link, and enter information according to the page prompts to query the bank of account.