We are using a billing agreement on Paypal. As a customer you can subscribe to a standard plan which is 55€/month and to a premium plan which is 95€/month. There is no period of notice if you want to cancel your subscription.
Is there a way to upgrade from standard to premium and get a discount of the price of the standard Plan on your first payment? (95€ - 55€ = 40€ on your first billing cycle)
https://developer.paypal.com/docs/api/subscriptions/v1/#subscriptions_revise - this is what I found in the docs, but that's not exactly how I want it to work, because I want the customer to have immediate access after upgrading a plan and not wait until next billing cycle. But if I grant him immediate access, the customer can cancel anytime before his next cycle and get free premium content.