Hi Michelle.

It's nice to have you here on the Community page. I can share with you the steps on how to reclassify transactions in QuickBooks Desktop (QBDT).

Yes, you're correct with reclassifying transactions at once. To use the Reclassify Tool, you need to have QBDT Accountant, Enterprise, or Accountant Enterprise version/s. If you don't have the same version of QuickBooks, you can still perform the process manually.

Here's how:

1. Open each transaction (a bill, invoices, checks, and others).
2. Make the necessary changes and update the class/division.
3. Click Save and Close. 
4. Replicate the steps for the rest of the entries.

You can also run a report and group them by class to locate your transactions easily. For additional resources about running and customizing your reports, I recommend opening this article: Understand reports.

On the other hand, yes, you need to select the appropriate classes per line item if you want to link each item to a different class. However, if you want to associate all items to a single class, you can select a single class under the Bill Due date section.

I've added these screenshots for your visual references.

To learn more about the class tracking feature in QuickBooks Desktop, you can open this link: Set up and use class tracking in QuickBooks Desktop.

Moreover, you can also check out the topics from our help articles for more tips while working with QuickBooks in the future.

If there's anything else you need help with reclassifying transactions in QBDT, please let me know by adding a comment below. I'm always here to help. Have a good one!