Google’s new Android developer verification rules take effect today in four countries, marking the biggest change to Android app distribution in years.

From September 30, apps installed on certified Android devices in Brazil, Indonesia, Singapore and Thailand must be registered to a verified developer. Developers must prove their identity and register package names with Google, whether they distribute through the Play Store or independently.

Google says the change fights malware, citing internal analysis that found far more malware in sideloaded apps than in Play Store apps. Full verification costs 25 dollars and needs government ID.

The open-source F-Droid store, which released its 2.0 rewrite days ago, calls the policy an existential threat since it signs most apps with its own key. Critics say the rules end Android’s open-install tradition. Google plans a global rollout in 2027, with an “advanced flow” promised for experienced users.

The seven participating stores include Google Play, Samsung Galaxy Store and Xiaomi GetApps. Developers who miss the deadline risk having their apps blocked on certified devices in the four countries.