Slashdot has reported:

Google has made phone number verification an opt-out feature on Android, automatically verifying the number on a device and associating it with every Google account signed in there. The accounts can include secondary profiles, work accounts and throwaway handles.

Users have reported receiving unexpected confirmation emails from “noreply-phone-verification@google.com” saying their number was verified, according to Android Authority, which cited a recent Reddit thread. The feature is called “Phone number verification” in Google settings.

Google’s support documentation has long said it periodically re-verifies a device’s number to keep communication and recovery features up to date. The support page was revised sometime between August and October 2025 to state that verification is on by default and that the number is added to all Google accounts signed in on the device.

Android users can switch off automatic verification by opening Settings, tapping Google, selecting the All Services tab, then finding Phone number verification under Privacy & Security and turning off “Verify phone numbers automatically.” The change only prevents future linking. “[T]urning off the phone number verification toggle only prevents future linking,” the report notes. “If Google has already attached your number across secondary accounts, you will need to open your Google Account Personal Info page, head to Contact info > Phone, and manually remove the number from each profile where it doesn't belong.”

The setting therefore does not remove numbers already associated with accounts. Those must be deleted manually from each Google Account Personal Info page where they do not belong.