The Duration Type of the coupon deals with the recurring functionality of coupons. This specifies how long a coupon can be applied to a subscription after being added.
There are three types of durations:
One Time coupons can only be used once in a subscription and cannot be used again after being redeemed. Once the discount is applied to the initial charge, the coupon will no longer be applicable.
Forever coupons do not have an expiration time set, and the discount will be applied as long as the subscription is active.
Limited Period coupons will have a fixed time duration. Once this time is over, the coupon can no longer be applied to the subscription.
If the coupon is set for three months, then the discount will be applied only for the next three months. After that, normal plan charges will incur.