Android links SIM numbers to every signed-in Google account

Android automatically verifies a phone’s SIM number during setup and attaches it to every Google account signed in on that device, including work and secondary accounts. Engadget reported the behavior on October 24, citing Google’s support documentation.

This is not a new rollout: the setting has been on by default since September 2025. A Google Play services changelog dated September 8, 2025 describes automatic verification during setup. Engadget reports that users are discovering the setting through unsolicited emails telling them their number has been verified.

The links extend to later accounts and SIM changes

According to Google’s support page, as described by Engadget, the setting covers existing and future accounts and numbers. An account added later receives the numbers already on the phone. Changing SIM cards also adds the new number to every signed-in account.

Google and the mobile carrier periodically verify those numbers again, which can incur carrier charges. The automatic-verification setting can only be managed from the phone itself.

What Google says verification supports

Google says verification enables account recovery and RCS, a messaging standard used by Google Messages. Google has not explained why the number needs to be attached to every account on a phone.

Engadget also reports that enabling verification turns on Better sharing on Google for one signed-in account. Google says that setting supports video calls, messages and notifications for content sent to the number, such as photos.

Google’s account help pages describe a separate setting, Better ads & Google services, that uses a phone number across Google services to show more relevant ads. Google has not said which advertising setting applies to automatically attached numbers. The company says it does not sell personal data, including phone numbers.