Hello, Edward111.

Thank you for reaching out to the Community. Processing a refund against a customer in QuickBooks Online is a simple process that can be completed in just a few steps. To begin, we can create a credit note and locate the customer you need to process the refund.

Create a credit memo:

• Select "+ New" and then "Credit Note."
• Choose the customer for whom you want to issue the refund.
• Enter the amount to be refunded in the "Amount" field.
• Save and close the credit note.

Once done, create a receive payment to apply the credit note to the customer's invoice. If the customer has multiple outstanding balances, ensure you enter the correct amount to be refunded to avoid confusion. 
 

• Select "+ New" and then "Receive Payment."
• Choose the customer and ensure that the total credits equal the credit note and invoice listed under "Outstanding Transactions."
• Tap the credit note and invoice checkboxes in the "Outstanding Transactions" section.
• Save and close the transaction.

Once done, QuickBooks Online will automatically update the customer's account balance to reflect the refund, and the customer's account balance should now be zero. 

Additionally, here's an article on how to apply a refund to a customer you process through QuickBooks Online.

Keep in touch if you need further assistance managing customer transactions in QuickBooks. I'll be around to help you more. Have a wonderful day, and stay safe!