Official comment
Today we added the ability to send an invoice on each payment of a Subscription or Payment Plan. For existing contacts you can enable recurring invoices to be sent by editing the Subscription or Payment Plan on the Purchases tab of the Contact Record.

Order Forms now contain a checkbox to automatically generate the recurring invoices for all future orders. You can edit your existing Order Forms in ONTRAPORT and the change will propagate wherever the form is published (so you don't have to re-embed the form code).
