whip7

[honest vapor]

that's not how it works; 20pff would be the https://stripe.com/docs/api/promotion_codes/object#promotion_code_object-code of the PromoCode object, you need to pass the id of promo_xxxx for example instead

you can use https://stripe.com/docs/api/promotion_codes/list#list_promotion_code-code to map user input to the promo code(or use our frontends like Checkout which handle all this)

[oblique nova]

I'm confused. I'm using this api https://stripe.com/docs/api/subscriptions/update. It has a property called promotion_code. I'm setting it to '20Poff'. This is the code of the coupon that already exists in my account. It was created from the dashboard long time ago.

Does promotion_code need to be an array?

My coupon doesn't seem to have a promo_xxx id. Its url is https://dashboard.stripe.com/test/coupons/20Poff

[honest vapor]

a Coupon is not a PromotionCode

you can't pass the coupon ID to promotion_code

if you have a coupon ID, you pass that to https://stripe.com/docs/api/subscriptions/update#update_subscription-coupon instead

[oblique nova]

Oh I see. Which should I use if I want to give a discount to a customer with a running subscription?

The subs is created without a coupon. I want to give a discount on the next payment

[honest vapor]

well a coupon

a Coupon is what applies a discount to the subscription. A PromotionCode is a separate object for a different use case(it's a way to let an end-customer enter a code and then you can look up the corresponding Coupon object and call the API to apply that Coupon to the subscription to do the actual discount).