Commerce License Billing provides advanced (prepaid, postpaid, prorated, plan-based, metered)
recurring billing for licenses.

Getting started
---------------
1. Go to admin/commerce/config/license/billing-cycle-types and add a billing cycle type.
2. Create a product, select a license type, then below select your billing cycle type
and billing type (prepaid or postpaid).
3. Checkout the product. If you selected postpaid as the billing type, your product
will be free.
4. A billing cycle has now been opened (with the current start date, and the end date
depending on your billing cycle type settings), along with a matching recurring order.
5. When the billing cycle expires, the recurring order will be closed and charged for
using Commerce Card on File, and a new billing cycle & order will be opened.

For more information see the documentation at https://drupal.org/node/2127603