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IMSS  /  Services  /  Information Security  /  Duo MFA  /  Authentication Methods  /  Duo Mobile passcode

How to use Duo Mobile passcode

Duo Mobile passcode is one of many authentication options available with Duo, and the second authentication option using the Duo Mobile app (along with Duo Mobile Verified Push). In most cases, Duo Mobile passcode is not as convenient as other methods, like Duo Mobile Verified Push. However, Duo Mobile passcode can be used even without an internet connection on your mobile device, so it can be useful in situations where mobile data and/or Wi-Fi are not reliably available.

How Duo Mobile passcode works

After you log in with your username and password, Duo prompts you to "Enter your passcode". In the Duo Mobile app, you will find a 6-digit passcode. Enter that passcode into the Duo prompt to complete the authentication process.

How to set up Duo Mobile passcode

If you have already set up the Duo Mobile Verified Push option, you are ready to use Duo Mobile passcode as well. If you have not, please see the instructions to set up Duo Mobile Verified Push.

How to authenticate using Duo Mobile passcode

  1. Log in to a Duo-protected service using your username and password
  2. Duo will prompt you to "Enter your passcode". If you do not see the this prompt, Duo may have defaulted to a different authentication method. Click "Other options" and then "Duo Mobile passcode" to manually select this option. If you do not see "Duo Mobile passcode" in the list of options, you have not set up this method yet. Refer to the instructions above.
  3. Open the Duo Mobile app on your mobile device and find the 6-digit passcode next to Caltech.
  4. Enter that passcode into the Duo prompt and select "Verify" to proceed.