When you enter a single activity, you'll see a "Billable"
checkbox in the Time/Enter Single Activity window.
A checkmark in this checkbox tells QuickBooks that you plan to invoice your
customer for this activity. When you record the activity, QuickBooks adds it to
the list of billable hours for this job. When you invoice your customer later,
you can transfer the hours directly to the invoice form.
If you are not going to invoice your customer, clear this checkbox (remove
the checkmark). The hours will not appear in the list of billable hours for
this job when you invoice your customer. They will, however, appear on any
reports that include this job. That way, you can track the hours you
don't invoice your customer for. On the Weekly Timesheet,
the Billable column should not be checked for an item if your
customer will not be billed for those hours.