Reactivating the Duo mobile app

This article provides guidance on how to troubleshoot specific issues with the Duo mobile app, mainly related to reactivation of the Duo app on your chosen device.


Important: If you have updated your mobile phone or chosen device's operating system software, purchased a new phone, or uninstalled the Duo app for some reason, you will need to re-activate the Duo mobile app.

Reactivating the Duo app

Provided your mobile number has not changed, you can do this without needing to contact the IT Service Desk.

Please use the guidance below to reactivate your device:

1. Go to (It is best to do this from a desktop or laptop).

Important: Your browser may remember you and automatically sign you in. In this case, please log out first, or use an Incognito or Private browsing window (How to Use Google Chrome Incognito)

Image displaying the Office 365 login screen

2. Enter your university credentials (email address and password).

Image displaying the Username and password fields

3. When the Duo prompt appears, click 'settings' in the top right and then 'My settings & devices'.

Important: You may have to click cancel first, if Duo has automatically tried to send a push notification to your device.


4. Authorise the Duo login via your currently-registered device.

Important: SMS Passcodes will still reach you if your mobile number is still accessible - you may have to click 'cancel' and 'dismiss' first if Duo has automatically tried to send a push notification to your device.

You need to use one of the options below.

You might need to use "Send Me a Push"(a notification sent directly to the Duo app installed on your chosen device) if you have a device with a working copy of the Duo app, e.g. an iPad.

You can use "Enter a Passcode" provided you still have access to the phone number that you registered on the Duo app originally.

If you chose "Enter a Passcode", this screen will appear next. You may already have a set of SMS passcodes; if you do not, please use the "Text me new codes" option.

5. After you've entered a code you will see a screen with your devices listed. Click the blue settings icon next to your registered device.

6. Click "Reactivate Duo mobile" and follow the instructions from here to finalise the process.

Further support and assistance

If you are experiencing any issues and require further assistance please refer to Duo two-factor authentication FAQs.

Important: If you no longer have the same phone number that you registered Duo with, this guidance will not help you. In this scenario, you will need to contact the IT Service Desk.

Back to top