Duo Mobile New Phone (app) that you can install on your smartphone or tablet to receive push notifications (and generate one-tap login codes) for easy authentication on the go. To improve the security of your logins, it works with Duo Security’s two-factor authentication (2FA) service. Using the Duo Mobile app is the preferred option because it’s free and allows you to easily approve second-factor authentication requests using Duo Push. If you are a Duo administrator looking for information on how to help end-users with common tasks like re-activating Duo Mobile, please see the Duo Help Desk Guide.

When you search for it in the App Store or Google Play, make sure that you select “Duo Mobile” with the green Duo logo on the cover, as shown above, and make sure you don’t pick any other app that has Duo in the title.

There are several reasons why this might be happening. To troubleshoot, make sure your registered device is connected to a cellular network or WiFi. You should have the Duo Mobile app open when you authenticate.

If you are new to Duo Mobile and installing for the first time on a new device, please see this guide for additional troubleshooting steps. We recommend that if you have previously used Duo Mobile on a smartphone, tablet, or other mobile device and are now moving to a new device, changing a phone number, or changing SIM cards, please refer to the information below.

Duo Mobile is tied to a specific device’s hardware security module (HSM), so you will need to reinstall and reactivate it on the new device. You can reactivate Duo Mobile in the traditional Duo Prompt or Universal Prompt via phone callback or SMS authentication if self-service device management (the “My Settings & Devices” button) has been enabled by your administrator. Account recovery can also be assisted by Duo Restore in the Duo Mobile app if Duo Restore was enabled on the old device. You can reactivate your duo mobile new phone accounts by contacting an IT administrator at your organization if you are unable to restore them through Duo Restore or other means. Troubleshooting will not be possible with Duo Support.

Follow the procedures for adding a new device in either the traditional Duo Prompt or Universal Prompt if you still have Duo Mobile installed and the ability to authenticate via push or passcode. Duo Push is not tied to the phone number, so if you haven’t deleted your previous device from Duo since your number changed and you reinstalled Duo Mobile on a new device, you will still receive pushes. The IT help desk at your organization can assist you if you do not have an authentication method. If you attempt to authenticate via SMS passcode or phone callback at this time, Duo will contact your old number. In the traditional Duo Prompt or Universal Prompt, delete the old device as soon as possible.

Because duo mobile is tied to the device’s hardware security module (HSM), you won’t need to reactivate the app after switching SIM cards. In the event that changing the SIM card also requires you to change your phone number, please see the previous section.