Until now, a coupon could only be added one way: a customer typing a promo code at signup. There was no way to see whether a subscription had one, or to change it afterward. Now there's a Coupon row right on the Subscriptions tab that shows the applied code (or "No coupon applied"), with an inline Edit action to add, swap, or clear it — and instant feedback on whether a code is valid. The same field is built into the Create Subscription tool, where a valid code updates the invoice preview before you submit. Comps, sponsored shares, and trade arrangements no longer need a manual back-end fix. Customers can see the coupon, but can't change it.