If you accidentally pay less than the total invoice amount, the amount received will be credited toward the invoice and the remaining balance will stay due.
How to Pay the Remaining Balance
You can pay the remaining amount in either of the following ways:
Option 1: Pay the Invoice Again
Go to your Client Area → Invoices, open the underpaid invoice, and click the Pay Now button to pay the remaining balance.
Option 2: Use Account Credit
If you have sufficient credit balance in your account, you can use your available credit to pay the remaining invoice balance.
Once the full invoice amount has been paid, the invoice will be marked as Paid automatically.