Hi there, @psalm33-9.

Can you share with me the steps you've taken to record your customer's overpayment in QuickBooks? The balance in your customer's accounts depends on how you record their transactions in the program.

That said, I'll share with you the right steps on how to record this transaction in QuickBooks. Here's how:

Step 1: Record the refund for your customer

1. Click + New and select Expense. 
2. Choose the customer you want to refund from the Payee ▼ drop-down list.
3. From the Payment account ▼ drop-down menu, select the bank account where you deposited the overpayment to.
4. On the first line of the Category column, choose Accounts Receivable.
5. Enter how much you want to refund in the Amount field.
6. Fill out the other fields as you see fit, then select Save and close.

Step 2: Link the refund to the customer's credit or overpayment

1. Select + New and click Receive payment.
2. Choose the same customer you used for the check or expense when recording the refund.
3. Fill out the other fields as you see fit.
4. Under the Outstanding Transaction section, select the checkbox for the Expense or Check you created when recording the refund.
5. Make sure the payment is equal to the open balance, then click Save and close.
    

You can follow these steps and delete the transactions when recording the first overpayment. That way, you can zero out your customer's balance in QuickBooks. 

For more info, please check out this article: Record a customer refund in QuickBooks Online.

In case you have follow-up questions about tracking a customer's refund in QuickBooks, please let me know. I'm always here to help. Have a good one.