Garmin Messenger raises privacy concerns over recycled phone numbers

This is one of those things that sounds harmless at first. A Garmin Messenger user says they installed the app on a second phone, verified their number by SMS, and their previous conversations simply appeared, without entering a Garmin account password.

They described the test in a Reddit post. In their case it was still their own phone number, so nothing bad actually happened. If you’re just moving to a new phone, having your chats come back automatically is actually pretty convenient.

The concern is what happens when someone no longer has that number. People give up phone numbers for all sorts of mundane reasons, such as moving country, ditching an old prepaid SIM, closing a work line or changing numbers without porting the old one. Mobile networks can eventually recycle those numbers and give them to someone else.

So the question is pretty simple. If the next owner of that number installs Garmin Messenger and verifies it by SMS, would Garmin also hand them the previous owner’s conversation history?

The concern goes beyond old messages

According to the user, the second phone didn’t just retrieve past conversations. It also became an active device for sending and receiving new Garmin Messenger messages. They say they couldn’t find a way to view other active sessions or remotely sign out the second phone.

Of course, SMS verification is a normal way to prove that you control a phone number. And the report doesn’t suggest that anyone can read chats simply by knowing that number. The question is whether Garmin adequately separates the previous owner’s messaging history from whoever can verify the number next.

Garmin Messenger is also more than a companion app for standalone inReach communicators. It is part of the company’s wider messaging setup, including the Fenix 8 Pro’s satellite and LTE features. It also supports related services such as Garmin Locate.

Uninstalling the app isn’t enough

Here’s a detail that Garmin’s own documentation does confirm. Once you verify your number in Messenger, incoming inReach messages addressed to that number route through the app rather than your phone’s normal SMS inbox. Removing the app from your phone does not, by itself, remove that association.

Garmin’s support instructions advise users who are leaving Messenger to open the app, go to Accounts, select Manage Garmin Messenger Account and choose Delete Garmin Messenger Account. This disconnects the phone number from Messenger without cancelling the separate inReach subscription. It is especially relevant if you’re changing numbers or giving one up.

The Reddit author says Garmin Support told them the app was working as designed and that the findings would be reviewed internally.

For now, the practical advice is simple: if you no longer plan to use Garmin Messenger with a particular phone number, remove its association before you lose access to that number. Better to be safe than sorry.