Items now can be included on a Time Billing invoice
Using Version 11, you can enter both activity slips and items on a time billing invoice. That is, you can create an a time and materials invoice!
If you want to be able to include items on a time billing invoice, simply mark the new preference "I Include Items on Time Billing Invoices." This preference has been added to the System view of the Preferences window. Locate the preference by choosing Preferences from the Setup menu; then choose the System view.
For more information about entering items on time billing invoices, see Entering activities and items for time billing invoices and Billing for time using the Time Billing Command Centre.