Decline Code 91: Issuer or switch unavailable

The decline code 91, which reads “Issuer or switch unavailable,” in a credit card transaction indicates that the transaction could not be processed because the card issuer or the payment switch used in the transaction was temporarily unavailable. This could be due to system maintenance, technical issues, or network problems preventing communication with the issuer at the time the transaction was attempted. As a result, the transaction cannot be authorized until the issue is resolved. It’s usually recommended to retry the transaction later or use an alternative payment method if the problem persists.