I've got some tips to help you manage Project and Class assignments for bills imported via CSV into QuickBooks Online (QBO), Cbrophy.

QBO doesn't have a built-in feature that automatically maps Projects and Classes when you directly import bills using a CSV file.

As a workaround, you'll have to manually assign bills after importing them to allocate projects and classes to your imported bills.

Here's how:

1. Go to My Apps on your QBO dashboard and select Expenses & Bills.
2. Find the bills you imported via CSV that lack assigned Projects or Classes.
3. Open the first bill and select Edit.
4. In the line-item details (under Category or Item details), use the dropdown menus to select the appropriate Project or Class.
5. Once done, click Save.
6. You'll have to repeat steps 3 to 5 for each remaining bills that requires assignments.

If you prefer a more efficient way to import bills with Project and Class information already included, you may also consider using a third-party app that integrates with QBO. These apps can automatically map additional details which can save you time and reduce manual effort.

With either method, you can maintain accurate tracking of Projects and Classes for all your imported bills.

Let me know through a reply if you need further help.