When creating an invoice. Projector searches for all billable time cards and cost cards. It then groups them onto invoices based on your scope. For example, if you invoice at the project level and a client has two projects, we generate two invoices.
If you have both time and cost cards to invoice - do you want them all together on one invoice or separated over two invoices? Some clients pay labor invoices more quickly than expense invoices or vice-versa. Billing for time/expenses separately may help your organization get paid faster.