iOS - Renewable In-App Purchases in an app that supports multiple user accounts on one device

Question

Background

My iOS app supports multiple user accounts, but the user can only be logged into one account at a time. The app also offers a subscription service ("credits" in the form of a renewable In-App Purchase).

I'm having trouble keeping the in-app subscriptions separated to the specific user account that bought them. If a user buys credits on Account One and then signs out, and another user signs into Account Two (on the same device), the SKPaymentQueue still proceeds with the renewal process for the purchases from Account One (and, consequently, triggers the logic that unlocks those credits).

Question

What is the correct method of handling renewable in-app purchases for an app that supports multiple accounts? Is there any way to keep purchases from "overflowing" into other accounts on the same device? What else should be kept in mind?

Answer 1

I'm pretty sure what you're trying to do isn't possible. In-app purchases are tied to the Apple ID that purchased them. That means that if the user is logged into an Apple ID that has purchased the subscription, you are always going to be told it is available. A single user can't purchase the same subscription multiple times. The only way would be to force an Apple ID change when they change users in your app, which I'm almost certain you can't do.