QuickBooks Online Sync Error: Cannot delete Customer: This customer cannot be deleted because there are unbilled charges for this customer

Why the Sync Error occurs

This error occurs when a deleted customer in PayMaker is trying to sync to QuickBooks Online (QBO), but the customer is linked to active/unbilled charges in QBO.

How to Fix the Sync Error

Reactivate the customer in PayMaker until the charges are completed in QBO, or delete the unbilled charges in QBO and sync again.