【中文版】

银行卡降级交易是指持卡人在进行交易时，所使用的银行卡芯片内嵌的芯片级别低于受理终端芯片级别，导致交易失败的情况。

随着芯片技术的发展，银行卡逐渐由磁条卡向芯片卡升级。由于芯片卡具有更高的安全性、稳定性和便捷性，越来越多的银行发行了芯片卡。然而，一些持卡人仍在使用磁条卡，或者在一些没有升级到芯片受理终端的场所使用芯片卡，这就容易导致银行卡降级交易的发生。

银行卡降级交易的原因可能是由于发卡行未对磁条卡进行升级，或者受理终端未升级到芯片级别。当持卡人在这样的情况下进行交易时，银行为了保证持卡人的安全，会采取降级交易的措施，将交易限制在磁条卡级别，以避免可能的安全风险。

对于持卡人来说，如果遇到银行卡降级交易的情况，可以向发卡行或受理终端所属机构咨询相关信息，以便了解如何解决该问题。另外，为了保障自己的账户安全，持卡人也应该考虑将磁条卡升级为芯片卡，以避免可能的安全风险。

总之，银行卡降级交易是一种保护持卡人安全的措施，但也可能给持卡人带来一些不便。持卡人应该及时了解相关信息，采取相应的措施来避免可能的安全风险。

【英文版】

Bank card downgrade transaction refers to a situation where the cardholder's transaction fails due to the chip level of the bank card used being lower than the chip level of the acceptance terminal.

With the development of chip technology, bank cards are gradually being upgraded from magnetic stripe cards to chip cards. Due to the higher security, stability, and convenience of chip cards, more and more banks are issuing chip cards. However, some cardholders still use magnetic stripe cards, or use chip cards in places that have not been upgraded to chip acceptance terminals, which can easily lead to bank card downgrade transactions.

The reason for the bank card downgrade transaction may be that the issuing bank has not upgraded the magnetic stripe card, or the acceptance terminal has not been upgraded to the chip level. When the cardholder conducts the transaction in such a situation, the bank will adopt downgrade transactions to limit the transaction to the magnetic stripe card level in order to avoid possible security risks.

For cardholders, if they encounter a bank card downgrade transaction situation, they can consult the issuing bank or the acceptance terminal ownership agency for relevant information, in order to understand how to solve the problem. In addition, in order to protect their account security, cardholders should also consider upgrading magnetic stripe cards to chip cards to avoid possible security risks.

In summary, bank card downgrade transactions are a measure to protect cardholders' security, but they may also bring some inconvenience to cardholders. Cardholders should timely understand relevant information and take corresponding measures to avoid possible security risks.