Does the import create duplicate customers in Quickbooks?

The import will use the Customer Name in Quickbooks to see if the customer already exists. It will compare the Customer Name with the First Name & Last Name in AssociationSphere. If it finds a match, it will create the transaction on that Customer record. If it does not find a match, it will create a new Customer.

You go to Account > Settings to specify if you use First Name Last Name or Last Name, First Name in QB.