I just picked up this thread, I am a fairly recent user of QuickBooks online, and selected the product because of its ability to use purchase orders and track inventory. To this point I have been creating an invoice as I work but this does not allow for job/customer margin tracking which is critical for business planning. As others have said here it is hard to understand why this feature has not been added as some comments here are 2 years old. I do understand that the inventory function is a separate module but certainly an interface can be created within the current framework.