Problem
Several invoices are imported into QuickBooks without classes assigned. You need to assign classes to the business units so the invoices export successfully.
Solution
You must have admin access in QuickBooks to perform the task below.
In QuickBooks Desktop, go to Settings in QuickBooks Desktop.
Click on your company file.
Select Business Units Assigned.
Map the business units to the appropriate classes.
Save the changes.
Export the invoices to QuickBooks.
Verify that the classes are now displayed in QuickBooks.