Currently we do not support deleting coupons or coupon codes. Once a coupon has been created you cannot delete it, instead you can opt to expire a coupon code. Coupons can expire automatically based on the rules you set for the coupon campaign, or you can choose to manually expire the coupon. Expiring a coupon blocks customers from redeeming the coupon. Customers who have already redeemed the coupon are not affected. Their active redemptions will continue to discount their accounts.
Coupons can be manually expired in an action we call Expire Early. To expire a coupon, visit the coupon's overview page and select Expire Early in the top right corner. This will ask you if you are sure you want to expire the coupon. Once you confirm, the coupon will expire immediately and will now live in the Expired Coupons table on the coupons dashboard.
This can also be done via the API using: https://dev.recurly.com/docs/deactivate-coupon.
Once a coupon is expired early or reaches it's maximum redemptions, the coupon code may be reused when creating a new coupon. Any existing customers with active redemptions from the original coupon on their account will be grandfathered into the terms of the old coupon.
We have more information on expiring coupons here: https://docs.recurly.com/docs/coupons#section-expire-a-coupon