If you need to access your order information after purchasing XLN Audio plug-ins from www.xlnaudio.com go to the XLN Audio website and click on My Account > View My Account. Go to Orders and it will list all your orders from www.xlnaudio.com. Clicking on one of the orders gives you detailed information for that order and you can select "View as PDF" to open up a downloadable PDF file as a receipt/invoice for the order.
If you or your company needs a specialized invoice before placing an order please get in touch with XLN Audio Support.