QuickBooks Online sync error: Customer has a non-zero balance in QBO

Why the sync error occurs

This error occurs when a deleted customer in Bill.com is trying to sync to QuickBooks Online, but the Customer has an open/non-zero balance in QuickBooks Online.

How to fix the sync error

Reactivate the customer in Bill.com until the customer has a non-zero balance in QuickBooks Online, or delete the customer's invoice(s) in QuickBooks Online and sync again.