Thanks for joining this conversation, @LeahC.

Let's work together running and customizing the Unbilled Costs report. It will help us locate the bills entered that were accidentally marked as billable.

1. On the top menu, click Reports.
2. Choose Customers and Receivables.
3. Select Unbilled Costs by Job.
   
4. Customize the date period.
5. Scan through the list. Click the Amount link to open the transaction.
6. Uncheck the Billable box.
7. Click Save & Close to save the changes.
   

That's it! Keep me posted if you have other report questions. I'm still here to help you more. Have a wonderful day ahead!