If you have a credit balance, you can use it to reduce or fully pay an invoice.

1. Log in to your client area.
2. Open the unpaid invoice (article 16).
3. If you have available credit, you'll see an option to Apply Credit Balance. Enter the amount and click Apply Credit.
4. The invoice total reduces by the credit applied. Pay any remaining balance as normal.

Note: Account credit can build up from refunds or overpayments. To see your balance, go to Billing > Add Funds or check the credit shown at checkout.