The “Expires in xx days” in the Coupon indicates that the coupon will expire in the “xx” specified time left. All Coupons are only available for a limited period. Each coupon may have different period of availability.
You can find the list of Coupons that are about to expire in the Expiring Coupon tab. Once a coupon is expired (after the specified xx days), it will no longer be available to be booked.
Make sure that you keep checking what coupons we have to offer you before they are expired!