I hear you! I was frustrated on two levels: (1) trying to determine why classes were not showing up on reports as one would expect, and (2) none of the "experts" clearly articulating that classes in QBO work entirely differently than in QB desktop/enterprise.

That word--"Class"--has significant weight and functionality in QB desktop/enterprise. It's a very effective way to create a reporting methodology that compliments the chart of accounts. However, there is nothing in the QBO documentation that says, "Wait. If you're a QB desktop/enterprise user, Classes in QBO work entirely differently and you won't get the results you may be expecting." Why Intuit chose to use the same word--class--then severely deprecate its functionality in QBO serves only one purpose: To frustrate its users. To me, it's a classic case of, "I'll program whatever I want and I don't care who it effects." Or, at best, the programming team in charge of QBO not talking at all to the folks who code QB desktop/enterprise.

The only solution for our organization was to touch every transaction and change its account, then delete the class--a complete waste of valuable time. I'm sorry you also ran into this significant issue, and I'm sorry that Intuit chooses not to fix the issue and that the answers in this forum danced around the actual answer: Classes are dramatically different in QBO. I hope you find a workaround.