Classes won't sync to QuickBooks Online from Bill.com on Receivables invoices if classes aren't set to per line (instead of one per entire transaction). They'll still sync from QuickBooks Online to Bill.com.
In QuickBooks Online:
- Select the Gear Icon
- Select Account and Settings
- Select Advanced
- In the Categories section, select the Edit icon
- Under Track classes, select One to each row in transaction
- Select Save