Invalid Transaction
An "Invalid Transaction" decline means the transaction type, format, or combination of details submitted isn't supported for this card, terminal, or account type. It's typically a technical or configuration mismatch — such as attempting a transaction type the card doesn't support — rather than a fraud or funds issue, and often requires a corrected resubmission.
Decline code by card network
| Card network | Code | Network's wording |
|---|---|---|
| Visa | 12 | Invalid Transaction |
| Mastercard | 12 | Invalid Transaction |
Common causes
- The transaction type requested (e.g. cash advance, refund, or a specific card-not-present flow) isn't supported for this card product.
- The card type doesn't match the transaction being attempted, such as using a debit-only card for a transaction requiring credit capability.
- Required fields in the transaction message contain an invalid combination of values, such as an incompatible entry mode and transaction type.
What merchants should do
- Verify the transaction type being submitted matches what the card and terminal actually support before retrying.
- Check your POS or gateway configuration for the specific transaction, such as a refund or pre-authorization, that triggered the decline.
- If the issue persists across multiple cards, contact your processor to confirm your integration is sending correctly formatted, supported transaction types.
How to prevent this
- Test all transaction types your business uses, such as sale, refund, void, and pre-auth, in a sandbox environment during integration.
- Keep POS and gateway software updated so new card products and transaction rules are supported correctly.
- Train staff to recognize which transaction types, such as manual key-entry or cash advance, require special handling or aren't universally supported.
Invalid Transaction declines are most common with less frequently used transaction types, such as cash advances, certain refund flows, or manual key-entry on terminals not configured for them. Reviewing exactly which transaction type triggered the decline is usually the fastest path to a fix.
Frequently asked questions
What's the difference between "Invalid Transaction" and "Invalid Amount"?
"Invalid Transaction" flags a problem with the transaction type or its combination of details, while "Invalid Amount" specifically flags a problem with the amount field itself. Both are technical or format issues rather than fraud or funds problems.
Can the customer do anything to fix this?
Usually not — this decline points to a mismatch between the transaction type and what the card or terminal supports, so it's the merchant's payment setup that needs correcting, not the customer's card or account.