In order to make hours billable, they must be against a Cost Plus Contract Job or Time & Materials Service Ticket.
Hours become billable if they meet the following requirements:
- The billable tag is on
- They are against a T&M deliverable
- The hours are approved
Hours are automatically marked as billable unless it is specifically turned off. To toggle this in the Review Time section, you can edit the time and make sure the box is checked as shown below: