Discover Payment Decline Code
Discover Decline Code 31: Bank Not Supported by Switch
Category Issuer or Network AvailabilityRetry Guidance Conditional Decline (Editorial Classification)By Payment Defender Editorial TeamUpdated July 17, 2026Last reviewed July 17, 2026
What Discover Decline Code 31 Means
Discover decline code 31 (Bank Not Supported by Switch) indicates that the cardholder's bank is not supported by the routing switch for this transaction.
Where the Response May Come From
Code 31 means the routing switch could not reach or does not support the indicated issuing bank for this transaction. It reflects a routing or participation condition, so the processor response is the reference for handling.
Common Reasons for This Response
Common causes include routing configuration gaps or an issuer not reachable through the current switch.
Should the Merchant Retry the Payment?
A retry may or may not help depending on whether the routing condition is momentary or persistent; confirm with your processor rather than assuming a plain reattempt will succeed.
Recommended Merchant Action
Check routing configuration with your processor, and if the issuer genuinely cannot be reached, ask the customer to use a card from a supported bank.
What to Tell the Customer
Let the customer know the payment could not be routed and suggest trying again shortly or using a different card.
How to Reduce Similar Payment Failures
Tracking code 31 by issuer BIN helps identify routing gaps or unsupported banks so you can adjust configuration or guide customers to workable options.
Important Limitations
Decline-code meanings vary by processor, gateway, and payment environment, and issuers do not always disclose the specific reason behind a response. The retry classification on this page is Payment Defender editorial guidance, not an official network rule. Merchants should confirm handling with their processor or gateway.
Related Decline Codes
Sources and Review Information
Last reviewed July 17, 2026
Raw network-response codes are supplemental to the complete processor or gateway response. Meanings and recommended actions can vary by issuer, processor, gateway, card network, payment method, region, and merchant configuration.