Invalid Merchant
What it means
The merchant account or identifier is not recognized or not valid for this transaction.
Why it happens
The merchant ID is not set up correctly, is not enabled for this card type, or the acquirer does not recognize it.
If you’re the cardholder
This is a merchant-side issue; try again later or contact the merchant.
If you’re the merchant
Check your merchant account and acquirer configuration; contact your acquirer to resolve setup issues.