When you choose the fields to import be sure to check Customer Name. At the bottom of the selections there are several fields you don't need, (Transaction Period, Transaction Number, Return Auth, Voided by Trans, Retainage Percent and Recur Number). Recur Frequency for annual is the number 6. You should enter a transaction then run the export for Sales Invoices with the headers. Open the csv file in Excel so you can review the information needed to import the data. If you want to try to import this file, just change the invoice number, save it, then import it. Make sure you do a backup before you import.