You may use
the credits included in the subscription plan you have purchased for the entire
duration of its validity.
Any credits not used during the subscription period
will be forfeited and cannot be accumulated, transferred, or refunded.
If you have
subscribed to a plan and you use up all the credits included in your
subscription, you may choose to add more by purchasing credit-only packages
(On-Demand).
Any on-demand credits purchased and not used during the validity
period of your profile will be forfeited and cannot be accumulated,
transferred, or refunded.