There's now a quiet change on Android devices: when a Google phone number is added to one account, it's automatically added to other accounts on the same device. Moreover, this is not a new feature. It's been on by default since the Google Play services update in September 2025, but users only noticed now.
Google's goal is thought to be to make account recovery easier and reduce abuse. However, the increase in conversations brought the privacy and security aspect of this feature to the agenda.
The problem is that the verification is done without confirmation from the user. For this reason, people may not realize that accounts they want to keep separate are linked. Most of us use different accounts for business, personal and sensitive services. Additionally, the number link connects these identities to a single real person.
On the security side, the phone number may be the only weak point. If fraudsters access SMS through methods such as SIM card swapping, they can obtain password reset codes. Although SIM access alone is usually not enough, it can be a gateway to large-scale attacks. Google, on the other hand, recommends Google prompts instead of SMS codes.
Additionally, a number can be used by different people over time. For example, the parent's number may be passed on to the child, or the operator may reinstate vacated lines. In this case, there is a risk of unintentional merging of identities. Even if the number changes, it is unclear how long the connections last.
This is not a vulnerability, but a deliberate feature. But users have the right to request approval. Turning it off is pretty simple:
Step 1: Enter Google from Settings, switch to the All services tab. In the Phone number verification section under Privacy and security, turn off "Auto-verify phone numbers."
Step 2: Manage your Google Account from the same screen. In the personal information section, delete numbers that do not belong to you or are not in use, and remove connections to devices you do not recognize.
Step 3 (optional): Review your sessions in Security and data sharing in Connected apps.
Some readers report that the setting turns back on after a while. That's why it's good to check it from time to time.
Instead of two-step verification via SMS, you can switch to Google Authenticator or passkeys. To do this, simply enter 2-Step Verification in the Security section and follow the on-screen instructions.
There is also an advanced method for those who want to separate accounts completely. On Pixel, you can add new users by following Settings > System > Multiple users. On Samsung Galaxy, Secure Folder under Security and privacy allows you to open a separate Google account in an isolated environment.
However, this setup breaks up the workflow and requires switching between users or folders. So it is necessary to take this into account before adding a new user. For those who want to limit Google phone number connection, the first step is to turn off automatic verification.
