Organize by Client FIRST then by project OR move invoices between projects

Because Designfiles is set up by project first rather than client first, i have designers creating new invoices in a new project where they should have created it in the ongoing project. I do not see a way to move the invoice from one project to another since it's the same client. I t would be Great if Designfiles could be organized first by Client and then by Project. However in the meantime, it would be great to be able to move an invoice from one project to another. Because right now, the only way i see to fix these errors is to delete the invoices and re-create them from scratch.