QuickBooks uses credit memos when a customer gets a refund for a product or service and receives store credit. These credits appear in the Accounts Receivable register within the Customer Center. Credit memos increase the available credit on the customer's account. You can delete or void a credit memo to remove the credit available to the customer. Voiding the credit memo reduces the available credit while still leaving a record in your transaction history for reference purposes.
Click the "Customers" menu and select "Customer Center" from the drop-down list.
Select the "Customers & Jobs" tab.
Choose the customer with the available credit from the customer list.
Open the credit memo you want to delete.
Click the "Edit" menu. Select the "Void Credit Memo" or "Delete Credit Memo" option from the drop-down list, depending on your preference. If you receive a warning that voiding the memo changes any attached invoices select "Confirm."