Symptoms
A device (mobile phone, security key, security token, etc.) that you use for Microsoft multifactor authentication (MFA) at Texas Tech University has been stolen or is lost. You are concerned that someone else may use the device to gain access to your account.
Cause
Various
Resolution
Some devices do allow passwordless sign-in, while others only serve as a second factor of authentication in addition to your password. The safest thing to do is remove the device from your allowed MFA methods to prevent unwanted access.
If you believe that someone may have gained access to your account, please view the procedure for potential account compromises.
Outcome
The lost device cannot be used to sign in to your account.