Hey Otto,
You have that mostly correct:
- For switching between monthly plans: Yes, the change would be immediate with proration.
- For switching between annual plans: This depends on the value. If switching to a higher-value annual plan, the change is immediate. If switching to a lower-value annual plan (using the same currency), the change is deferred until the next billing cycle.
- For changing from monthly to annual: Yes, the change would be immediate with proration.
- For changing from annual to monthly: Yes, this would be deferred until the next billing cycle (assuming same currency).