1. Network or system problem: It may be that the network connection of the tax system or the banking system has failed, which makes it impossible to select a bank card. In this case, you can try to log in again or try again later, or contact relevant departments or banks for consultation and settlement.
2. Account or authority problem: Your bank card may not be bound or set as the default payment method in the tax system, or your account has limited authority and cannot be selected. You can log in to the tax system, check the bank card binding, and ensure that the account authority is sufficient for the selection operation.
3. Other reasons: There are other possible reasons, such as incompatible software versions and browser settings. You can try to update the software or switch to another browser, or consult relevant technical support personnel for help.
It should be noted that each specific situation may have different reasons and solutions. If the above methods are ineffective, please contact the tax department or bank in time for professional help and guidance.