This article covers
Meaning of Exhausted status of a coupon on a subscription
Solution
When a coupon has the status “exhausted” attached to it, it means that the validity of the coupon is over for that particular subscription where it is applied, and from the next renewal of the subscription, the coupon will not be applied and the coupon will be removed from the subscription details ribbon.
Related articles and Documentation
https://www.chargebee.com/docs/2.0/coupons.html