1. macOS & iOS
Upgrade. When a customer switches from a subscription at a lower level to a subscription at a higher level. The customer’s prorated amount from the prior in-app purchase is refunded to the original payment method. The new in-app purchase is charged and goes into effect immediately at the full price, which changes the customer’s renewal date to the upgrade date.
Downgrade. When a customer switches from a subscription at a higher level to a subscription at a lower level. Customers will be billed the new rate on their next renewal date.
2. Windows, Web & Android
Upgrade: When a customer upgrades to a higher plan it will instantly get upgraded, if there is any action plan it will be settled down with the new one. For example: if a customer upgrades from Silver to Silver Plus then the prorated amount of the remaining Silver Plan duration will be settled with the Silver Plus plan charge. The amount will be settled with the new purchase.
For the web and Windows, there is no functionality for this, but this will work in Android apps. If a customer downgrades from bronze to gold then after the gold plan expires the bronze plan automatically activates.