Yes. If a project or phase is marked as Completed while it still has unbilled time or expense entries, those entries can be billed. You can bill logged time and expenses, but cannot log new entries against it. You are prompted if the projects have unbilled (billable) time and expenses associated with them. These entries can be billed after the project is assigned the Completed status. You can also bill pending invoices and record payments against these projects. Completed projects do not appear in the drop-down lists except for billing and A/R.
Note: When the project status is changed to 'Completed' and there are no unbilled time and expenses, the project rule Always show in Create Batch Invoice screen is automatically turned off in CORE.