I have a monthly plan that uses a fixed price as well as graduated pricing i.e., 50 units included per month and 10 cents per additional unit of usage. If a customer's usage is below 50 units I want to rollover the remaining included usage to next month.
How can i do that in Stripe Subscription?
Unable to find any instruction to setup rollover usage.
Stripe does not have pre-built functionality for this type of scenario, if this is something that you would like to handle then you will need to build your own code/solution to do so.
To do so you will likely want a place to track the excess that is being rolled over from previous billing period, and then for future billing periods you would first deduct overages from that running balance before adding Usage Records to the Subscription Item to update its usage in Stripe, but exact implementation details will vary based on your requirements.