Error code
Card Network 12
CARD NETWORK12
Payment Decline Code· Why a card payment was declined by the issuer or processor, and what to do.
What it means
Invalid Transaction.
How to fix it
- Verify the transaction type is supported by the card.
- ask the customer for a different card.
Not affiliated with Card Network. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.