Can I edit classes for inventory items using a mass update function?

No it is one at a time

I did that, but when I click on an item, I don't see the class field with a drop down list in it?

Exactly. Even doing this one at a time, where is the class field inside the Edite item screen?

Exactly. Where is the class field within the edit item screen? Maybe I'm in the wrong screen? Bummer than it cannot be done en-mass, but how is this done for an individual item?

Hi there, Sloth22. 

Thank you for giving information about your concern and for following the steps recommended by my colleague. I can share additional information on how you can add a class column in QuickBooks Desktop. 

You'll have the option to add classes if you're using the QuickBooks Desktop Accountant and QuickBooks Desktop Enterprise Solutions versions. Then, assign a class to Accounts, Items, and Names in QBDT depending on your preferences. 

Here's how:

1. From the Edit menu, choose Preferences on the drop-down.
2. Select Accounting from the left pane, then choose the Company Preferences tab.
3. Under the CLASS section, put a checkmark to Use class tracking for transactions.
4. Check the box beside Assign classes to, and then select Items on the drop-down menu.
5. Click OK.

Once done, you can follow the steps below on how to add class columns in QuickBooks Desktop.

1. Go to Lists at the top menu and select Item List.
2. Right-click on the Item and select Customize columns.
3. In the Customize Columns - Item List window, go to the Available Columns field.
4. Select Class and click the Add > button.
5. Once done, click OK.

Also, here's an article that'll further guide you in filtering and sorting class transactions through reports by class in QBDT: Categorize data by class. It includes topics about unclassified transactions and reports showing subclasses only, to name a few.

In case you need additional assistance in managing your classes in QuickBooks, please get back on this thread. I'm always here to help.