Apple specifies grace period for third-party app store access when leaving the EU
If you were left wondering what Apple’s “gone for too long” policy towards users who have sideloaded apps and leave the European Union – it’s 30 days. Apple updated its support page to clarify the grace period is exactly 30 days after which users will not be able to download apps from alternative app stores or receive updates to downloaded apps. You can still use third-party apps outside the EU indefinitely but software updates to those apps will be unavailable after the 30-day grace period.
In the specific case where a user is outside the EU for 30 days and returns to EU territory, they will again be eligible to update apps downloaded from third-party app stores. Using the new iOS 17.4 app sideloading feature requires that you are physically located in one of the 27 EU member states or their overseas territories.