If you want to connect a Project with an estimate, go to the ‘Project Activity’ tab in the Project Dashboard (Time & Projects, Projects, Click on the Project name you need, Project Activity):

Click on ‘Connect estimate’ and choose one or several estimates (this list include only the estimates created for this project’s client):

Click ‘Connect’ and from now on, you will see these Estimates’ activities on the ‘Project Activity’ tab:

Connect invoices

You can also connect invoices with projects in the same way as you did with the estimates. These invoices should be paid and not assigned to any other project.

You can disconnect the manually attached invoices at any time.
But in this table you will also see invoices that cannot be disconnected – these invoices have timesheets/expenses attached related to this project. Therefore, if you attached such timesheets/expenses (more here) to the invoice and pay this invoice – it will be displayed here automatically.