Has anyone realized that if you deactivate a class or subclass, that now that associated data is completely eliminated from reports - giving a totally inaccurate report.

Thanks for sharing your concern here in the Community, @user59084. I'd be glad to discuss how classes work in QuickBooks Online (QBO).

When you reactivate inactive classes in QuickBooks Online (QBO), the data associated with those classes is brought back.

Initially, classes are used to categorize financial information for thorough reporting, but the transactions will continue to be present in QBO regardless of the class status.

It's important to know that when you deactivate a class, it doesn't detach the data from your past transactions that were associated with it; instead, it just prevents that class from being chosen in future transactions and from being included in financial reports filtered by Class.

After inactive classes are reactivated, it's possible that the transactions previously linked to those classes were included in the P&L Comparison reports filtered by Class.

Moreover, I am giving you this article for your future reference if you want to export your reports: Export reports, lists, and other data from QuickBooks Online.

Feel free to post if you have further concerns about managing your transactions in QuickBooks Online.