The QuickBooks integration has two components:
NOTE: Full Web Services integration is available only to merchants who use QuickBooks Merchant Service as their payment gateway. If you are not using QuickBooks Merchant Service, you can use Quick Shopping Cart Web Service to send receipts to QuickBooks. However, the receipts will not be integrated into the QuickBooks Merchant Service functionality that allows credit card reconciliation within QuickBooks.
For more information on using QuickBooks, refer to the QuickBooks Quick Start Guide.