DECLINE CODES · 12

12 · Invalid transaction

FIX & RESUBMIT
WHAT THE ISSUER IS SAYING

The issuer can't make sense of the request — wrong transaction type for this card or merchant setup. Often a configuration problem on the merchant/processor side, not a card problem.

WHAT TO DO

Don't burn retries. Check with your processor: MCC setup, transaction type flags, currency configuration.

THE CATEGORY

Fixable: something in the request is wrong. Correct the data and resubmit — this isn't a judgment on the customer.