In QuickBooks Online (QBO), the Amount to credit appears when a customer payment exceeds their total balance or when there are no open invoices to apply the payment to. QBO holds that extra money as a prepayment for the future.
Here are the most common reasons why it arises:
Overpayment: Customer pays more than the invoice balance.
Payment without invoice: A customer sends payment when no open invoice exists, QBO will prompt to save as credit.
Partial payment then refund: After a partial payment is refunded, the credit will show on the receipt.
This credit remains in your Accounts Receivable and can be applied to a future invoice or refunded at any time.