APNs may start returning an “error” (410 status) for tokens if it has determined that a particular token is no longer in use. To make this determination, the device itself must report back to APNs that it is no longer accepting notifications for the app. This happens only if an app has been deleted on a device that is otherwise in use, and then a notification is sent to the app once, then the token will be marked as "not in use".
To avoid developers from detecting and tracking user behavior around installations and uninstallations, APNs will start returning a 410 status for these tokens on a fuzzy schedule. This schedule is not documented, and can change at any time. This is for protecting the users’ privacy, and is by design.
You will find many edge cases where the token may no longer be in use, but you will always get a success status for it. Trying to determine whether an app has been deleted or not, based on the 410 status is an off-label use that would not guarantee the results you might expect.
If you are worried about wasted token processing, you may want to look into solutions in your app that could perhaps determine that the user is no longer using that particular instance of your app - perhaps they did uninstall, or they changed devices, etc.
Argun Tekant /
DTS Engineer /
Core Technologies
