# Re-authenticating under Tailnet Lock

Last validated Jan 5, 2026

When Tailnet Lock is enabled, each of your nodes stores tailnet-lock keys and other important data that should be preserved. As such, it's important to re-authenticate your existing nodes when they expire, rather than login again.

## I got an error logging in, what should I do?

If you receive the following error after attempting to login:

```
You have a locked tailnet and this machine has already been registered. Please either delete the machine from the admin console and retry, or switch back to the profile and reauth. https://tailscale.com/s/reauth-under-tailnet-lock
```

That means that your login would have overwritten an existing login on your device, resulting in the destruction of a Tailnet Lock key and a locked out node.

Instead, reauthenticate your existing login by switching back to it and re-authenticating:

```shell
tailscale switch <your-username>
tailscale up --force-reauth
```

If you did mean to overwrite your previous node with a new login, delete the machine from within the admin console before logging
in again.