Secure Mono after losing a device: access, linking, and reset
Learn how Mono app locking, device removal, and sync reset differ, and what to check before replacing a lost device or changing encryption keys.
A lost phone causes two separate problems: access to your Mono account, and the information already stored on the phone. Removing a device from your account is not the same as erasing its files remotely.
Use a device you still trust to review access, and use your phone’s own lost-device tools for the missing hardware. This guide explains the controls in Mono by Reunified and what each one does and doesn’t do. Mono isn’t out yet (join the waitlist); before any reset, read the confirmation the app shows you.
1. Protect the missing device through its operating system
Follow the official Apple lost-device instructions or Google lost-device instructions, depending on your device. What’s available depends on the device and how it was set up. Removing the device in Mono doesn’t replace those tools.
On a device you still trust, open Mono and check that you can reach the information you need. Don’t start by clearing the app’s data or reinstalling it on your last working device; that can make recovery harder.
If you’re not sure whether an action blocks access, changes encryption keys or deletes data, read its confirmation before you continue. These actions do different things.
2. Inspect the device list
Open Settings → Profile → Devices. Find the missing device by its name, model, and last used or last synced time. A similar name isn’t enough if you own several devices.
The times shown can be out of date while you’re offline, so an old time is a clue, not proof that the device is offline or signed out.
Note which device you want to remove. Keep your trusted device on and connected while you change access. If a refresh or action fails, reconnect and check the list again before you assume it worked.
3. Remove one device when that is the intended scope
Open the other device’s details, choose Delete and read the confirmation. This removes the device from your account. It loses access to your synced data and has to sign in and be linked again to get it back.
It isn’t a remote wipe: data already on that device stays there. Deleting one device also doesn’t change your sync encryption key; only the broader reset below does that.
If you see an error, part of the action may already have worked. Refresh the list and check what access remains instead of assuming nothing changed. Use the broader reset only when you actually want its extra effects.
4. Understand the broader sync reset before using it
Remove other devices is a different action. It signs out every other device, changes the sync encryption key, unlinks all other devices and wipes the synced copy on the server. Data already on each device is kept, and the other devices must be linked again. It can’t be undone, and it won’t bring back missing history.
| Action | What it’s for | What to keep in mind |
|---|---|---|
| Delete one other device | Remove that device’s account and sync access | Doesn’t erase the data on it |
| Remove other devices | Reset sync around your current trusted device | Wipes the synced copy on the server and changes the key |
| Link a device | Give another of your devices synced access | Check carefully that the pairing codes match |
Before a reset, check the data on your current device and save anything important with an export or a file backup. Don’t reset sync from a new, empty device expecting to get the old server copy back.
5. Link replacements from a current trusted device
Sign in on the new device and link it from a device that is already set up for sync. Make sure the pairing code comes from your own device, signed in to your account, and check that the verification codes match before you confirm.
Linking gives the device access to your synced chats and memories. Never approve a pairing request just because someone says support needs it. If Mono says a device sent a key your account no longer uses, link from an up-to-date device instead of trying the old one again.
If you have no trusted linked device left, signing in alone won’t bring back the encryption key or your old history. Starting fresh replaces sync; it doesn’t recover what was there.
6. Add protection before the next incident
On the devices you keep, turn on Mono’s app lock with biometrics, such as Face ID or Touch ID, or with a 6-digit passcode. You choose one method: biometrics and a passcode can’t be used at the same time. Check that you can unlock the app before you rely on it.
Look at the device list now and then, and remove devices you no longer use. Keep important project files and conversation exports in a safe place. The privacy guide explains why data on your device, encrypted sync and requests sent to an AI provider each need their own thought, and Mono’s privacy overview sums up app lock and encrypted sync.
