I know how helpful it is for your business to link an existing invoice to an existing quote in QuickBooks, @McN41R. Your satisfaction means everything to us.

As it stands, the steps described by my colleagues above are the closest solutions we can offer to link the transactions to the projects. But don't worry, I can help you make anything possible in QuickBooks.

With this, I'll route you to the page where you can post feature requests to our product engineers. It enables our engineers to develop a solution to enhance your overall QuickBooks experience.

Here's how: 

1. Go to the Gear icon on the upper right pane.
2. Select Feedback. 
3. Type your suggestion in the box and click Next. 

Many of the program's current features are available because of user feedback. Also, QuickBooks has a website where you can vote on and provide comments on any future suggestions. To access the page, visit this link: Customer Feedback for QuickBooks.

Further, check out these articles below on how to add paid/unpaid invoices to projects and other related topics: 

• Add existing invoices to QuickBooks Online Projects
• Add project estimate summaries to a progress invoice

Do you have questions about other processes? Add them to your reply, and I'll assist you. Keep safe, McN41R.