Hello there, @thegreenbuild.
You can rename the existing invoice to add to your project in QuickBooks. Let me guide you how.
- Go to the Projects.
- Click Add to project on the upper right, select Invoice.
- Click the drop-down arrow in the customer field.
- Look for the name of the project and select it. It should be right under the customer's name.
- Click Save and Close.
You can also use these articles to get more details on how the Projects feature works:
If there's anything else that we can do for you, don't hesitate to drop a comment below.