1. Bank card problem: the balance of the double-label credit card is insufficient or the bill has not been paid off, so the reservation cannot be paid.

2. Bank risk control: In order to ensure account security, banks will monitor transaction risks. The bank thinks that the transaction is abnormal or risky and will refuse the payment request.

3. Booking platform problem: Sometimes the booking platform itself will fail or have technical problems, resulting in the failure to complete the payment normally.

4. Double-label credit card is not within the payment card range supported by reservation.

In short, understanding the restrictions and regulations of banks and reservation platforms on double-label credit card payment and contacting relevant parties to solve the problem in time can avoid the situation that double-label credit cards cannot be paid online.