@Ryan_M Thank you for your response. You are the third QB Team member to respond. None of you have answered my question.
Each of you has introduced a new twist. As I requested clarification, no one has followed up. This thread is a series of non-sequiturs.
@Maybelle_S suggested my experience with Quickbooks was a browser malfunction. @DivinaMercy_N said I could use the Item Details in an Expense screen to identify Products/Services as I wanted, but I can't follow her directions, can't see where she got her screenshot, and I can't find anywhere in the QBO app that looks anything like what she's describing. And now @Ryan_M , you've not addressed my question of whether I can use the Products and Services List to provide more detail for Billable Expenses in an invoice. The two videos you link do not show the use of the Product/Service field and you didn't mention it at all.
I had created items in the Products and Services List that would serve my purposes well to provide more detail on the invoice for my clients about the Billable Expenses. But I can't use them because, when selected, they delete the data provided from the Billable Expense. I had hoped I was missing something, but after three responses, it appears I am not. It appears this is the way QBO is designed to work, which is to say, it doesn't. At this point, someone from QBO could simply admit that it won't work, but I'm past the point of expecting that.
