First, the status of the card is abnormal, such as card degaussing, chip damage, too many password input errors and being locked, etc. It is recommended that the landlord call his home service hotline to confirm.
Second, there is nothing wrong with the card. If the signal of POS machine is not good, the off-line transaction will fail.
Thirdly, if the landlord holds an IC chip credit card, because UnionPay has closed the downgrade transaction function, if the cashier still operates the transaction by swiping the card instead of inserting the card, it will not be available.
Fourth, the landlord's card does not support transactions. For example, the card of VISA single logo /JCB single logo card does not support UnionPay transactions, nor does it support some online transactions.
Fifth, some overseas websites do not support domestic credit cards or CCB credit cards.
If the landlord has other questions, you can ask.