How to Delete a Credit on Quickbooks, follow these steps:
Step 1: Go to your QuickBooks account's Customer menu, then select Customer Center from the drop-down menu.
Step 2: Select the customer from the Customers & Jobs page.
Step 3: Locate the credit memo you want to cancel and open it.
Step 4: Select the Edit option from the drop-down menu. Then, from the particular dropdown option, select Void Credit Memo and then Confirm.