Insufficient Funds
What it means
The card or account does not have enough available balance or credit to cover the transaction amount.
Why it happens
The available balance or remaining credit line is lower than the purchase amount, sometimes because of pending holds on the account.
If you’re the cardholder
Add funds, pay down the balance, or use a different card, then retry the payment.
If you’re the merchant
Treat as a soft decline and allow a retry later or offer an alternative payment method.