Stripe - Apply coupon to customer or subscription?

Question

In the Stripe API Documentation, they show that you can apply a coupon on a Customer.

cust = Stripe::Customer.retrieve("cus_asdasdad")
cust.coupon = "COUPONCODE"
cust.save

However, you can also apply a coupon on a Subscription:

cust = Stripe::Customer.retrieve("cus_asdasdad")
sub = cust.subscriptions.retrieve("sub_blablabla")
sub.coupon = "COUPONCODE"
sub.save

What is the difference between the two? Essentially, I'd like to give a customer $15 off their next subscription charge, and only the next one.

Answer 1

To make a coupon that can only be used once set the max_redemptions property to 1.

With regard to your question, the difference is that applying the coupon to the Customer will apply the discount to the sub-total of the Invoice created for that Customer. Meaning that if the Invoice includes a Subscription and multiple InvoiceItems, then the discount will be applied to the sum of all of them.

Conversely, applying the coupon to a Subscription only means the discount will be applied to the cost of the Subscription only. Other InvoiceItems within the Invoice will not be discounted.

Won't make a difference if the Coupon is a "20 dollars off" type, but it will if it's a "20% off" kind.

Answer 2

A coupon applied to a customer will apply to all future invoices and/or subscriptions, even if the coupon has expired, dependent upon how you set the duration attributes for the coupon.

A coupon applied to a subscription will only apply to that specific subscription.

The duration attribute will determine how long this discount will apply, either once, repeated, or forever.

The max_redemptions attribute limits the the total number of coupons that you are willing to honor, e.g. the first 100 customers.