Why the Sync Error occurs
This error occurs when a contact (customer, vendor, or employee) is trying to sync to Quickbooks Online (QBO) from Bill.com, but a contact of the same name already exists in QBO. All contacts must have unique names in QBO, regardless of contact type.
How to Fix the Sync Error
Edit the name of the customer, vendor, or employee in Bill.com so it is different than the existing contacts in QBO, and sync.
Note: We pay vendors using the Pay To field, so you can edit the vendor name field and it will not impact the payments.