To export your customers from QuickBooks desktop, navigate to the Customer Center in QuickBooks.
1. Click the "Excel" button in the toolbar, and choose "Export Customer List..."
2. Choose the option to export the customer file to a comma separated values (.csv.) file
3. Click "Export"
You will be asked where on your computer you would like to save the file.
Once saved, read this article on Importing Customers into ServicePal