How do I issue a complete refund of a paid invoice in BillQuick and still keep a record of it
Follow these steps to resolve the issue:
1. Debit the payment for an equal amount in the Payment screen in BillQuick. Uncheck Hide Paid Invoices. 
2. Select the Pay Method Debit and apply it to the previously paid invoice. This will reverse the payment and return the original balance to the invoice.
3. After entering the debit payment, it will appear in the payment history of the project and become an open invoice again. This open invoice can be either written off, adjusted using a credit memo or left as an open invoice.
4. Next, you can use your accounting software to issue the refund check. If you are using BillQuick Plus Accounting, then use the Write Checks screen to do so.
Note: If integrating with QuickBooks, please note that a debit (negative payment) will not sync to QuickBooks. You must issue a refund check manually to the customer in QuickBooks.