willRenew behaviour on cancelled but still active subscription [iOS SDK]

Hey ​@zdtorok ,

using unsubscribeDetectedAt is the recommended approach for detecting subscriptions that have been cancelled but are still active.

The willRenew flag can be delayed, which is even more noticeable during testing. This is due to how frequently these syncs with Apple happen when App Store Server Notifications aren't enabled.

So while technically accurate, it’s not timely unless server notifications are set up. As for your code snippet, it works because unsubscribeDetectedAt is a timestamp that reflects when RevenueCat detected the cancellation event and it’s explicitly meant for this use case.

For the most reliable, real-time behavior in Production, we recommend enabling App Store Server Notifications (V2). This ensures RevenueCat receives cancellation events from Apple immediately, without waiting for the next polling cycle.

NOTE: Be mindful of your current Restore Behavior setting and the limitations around having this enabled for certain types.

Using syncPurchases() can help during development or after login, but it does not guarantee receipt changes are reflected right away. Server notifications are the better long-term solution.

As for TestFlight and Sandbox renewal times, here’s a quick breakdown:

NOTE: TestFlight renewals were updated in Dec 2024 to always occur every 24 hours, regardless of duration. More context in our TestFlight testing section.

I hope this extra context helps in understanding the overall behavior - that said, you should be confident in using unsubscribeDetectedAt - it's the right tool for detecting cancelled but still active subscriptions like in your scenario.

Best,