Issue : Unable to integrate customer into QuickBooks Online from Salesforce even though the Salesforce Account does not exists in QuickBooks as a Customer.
Reason : Either a Vendor or Contractor or an Employee exists in QuickBooks with the same name as Salesforce Account, hence customer will not be created.
<Error code="6240" element="">
<Message>Duplicate Name Exists Error</Message>
<Detail>The name supplied already exists. : Another customer, vendor or employee is
already using this name. Please use a different name.</Detail>
</Error>
Solution: