Hello, ShannonFord.
Thanks for reaching out to the Community. As mentioned by one of my Colleagues, if you add a paid invoice to a project, the invoice will disconnect from the attached payment. That said, we don’t recommend adding invoices linked to more than one other transaction. If you add a linked invoice to a project, only the invoice is added. You’ll need to add the linked transactions to the project and reconnect them to the invoice.
Also, you can add existing estimates to projects as long as you haven’t converted them to invoices.
To give you more insight, you can review these helpful articles. This should point you in the right direction:
Don't hesitate to reach back out to me should you have any other concerns with QuickBooks. I'm always here to lend a helping hand. Have a good one!
