Under the "Invoices" tab admins can create, download and send invoices.
When you create a new invoice, you first get the choice whether you want to start with an empty template, or a template based on a project.
After creating the invoice you can change the template as desired before sending it to the customer.
When an invoice is sent, you cannot update or delete it anymore. When the expiration date has passed, the status will automatically become "Overdue". You can manually change the status to "Partially paid", "Paid" or "Written off".