In short: Duo Mobile is Cisco Duo's free authenticator app for iOS and Android. It approves logins with Duo Push and Verified Duo Push, generates passcodes that work without a signal, and can hold codes for third-party accounts. Duo Restore helps move accounts to a new phone; otherwise an admin or the self-service portal reactivates it.
What Duo Mobile does
Duo Mobile is the app your organisation's Duo account sends login requests to. It is free from the Apple App Store and Google Play, and the same app works for every Duo customer.
- Duo Push: approve or deny a login with a tap, from the notification or inside the app
- Verified Duo Push: type the code shown on the login screen into the app to prove the login is yours
- Passcodes: generate a one-time code in the app, which works with no mobile signal or Wi-Fi
- Passwordless: act as the authenticator for Duo passwordless login, and for Passwordless OS Logon on Windows over Bluetooth
- Third-party accounts: store time-based codes for other services that support authenticator apps
- Fraud reporting: tell your administrators straight away about a request you did not start
- Security Checkup: compare the phone's settings with Duo's recommendations, such as an up-to-date OS and a screen lock
Duo also has companion support for Apple Watch and Wear OS, so users can respond to requests from their wrist.
Supported phones
Duo Mobile runs on iPhone, iPad and Android. The current version of Duo Mobile needs iOS or iPadOS 17 or later, or Android 12 or later, and older versions have been removed from the app stores. Users on older phones should update the operating system if they can; if not, they will need another method such as a hardware token or security key.
Some features need a recent version of the app, so keeping Duo Mobile updated avoids most problems. Whether staff use their own phones or company devices on EE Business, O2 Business or Vodafone Business, the app works the same way. Company phones can have Duo Mobile pushed out through your mobile device management platform.
Setting up Duo Mobile
Most users set up Duo Mobile the first time they log in to a Duo-protected application:
- The Universal Prompt offers to set up Duo, or the user follows an enrolment email from their IT team.
- They choose Duo Mobile and install the app from their app store.
- They scan the QR code shown on screen with the app.
- They allow notifications, so push requests appear on the lock screen.
- They finish enrolment, and their next login can be approved with Duo Push.
We recommend adding a second method at the same time, such as a passkey or a second device, so a lost phone does not lock anyone out. See our Duo setup guide for enrolment options.
Moving Duo Mobile to a new phone
This is the most common Duo help desk request. There are two routes.
Duo Restore
If your administrator has enabled Duo Mobile Instant Restore and the user has a backup, their Duo-protected accounts come across automatically:
- iPhone: restore the new phone from an iCloud backup (with iCloud Keychain switched on) or an encrypted iTunes or Finder backup, then open Duo Mobile
- Android: restore from a Google backup (other vendors' cloud backups will not work), with a PIN, pattern or password screen lock set, then install and open Duo Mobile
- Restoring moves Duo-protected accounts to the new phone and deactivates them on the old one
- Backups cannot move between iOS and Android
- Third-party accounts need the recovery password set when backup was switched on; Duo cannot recover it. Restoring them does not remove them from the old phone, so delete them there once the new codes work
- Passwordless OS Logon accounts cannot be restored and must be enrolled again
Reactivation
If restore is not enabled or there is no backup, the user reactivates Duo Mobile. Where self-service is switched on, they can add the new phone themselves through the device management portal in the Universal Prompt (logging in with another method or a passcode). Otherwise an administrator sends a new activation link from the Duo Admin Panel.
Common Duo Mobile problems and fixes
| Problem | What to try |
|---|---|
| Push notifications not arriving | Check notifications are allowed for Duo Mobile; open the app, which checks for waiting requests; toggle airplane mode or turn Wi-Fi off and use mobile data; make sure the phone's date and time are set automatically; on iOS use the app's troubleshooting tool |
| Notifications stopped after reporting a push as suspicious | Duo mutes push notifications for 20 minutes after a fraud report; open Duo Mobile to approve a genuine login in the meantime |
| No signal | Use a passcode from the app instead of push, if your policy allows it |
| Verified Push code box missing | Update Duo Mobile; older versions cannot show the code field |
| Lost or stolen phone | Tell IT straight away; the device can be removed in the self-service portal or by an admin, and a bypass code issued |
| App will not install | The phone's OS is too old: Duo Mobile has been removed from the app stores for iOS 16 and earlier and Android 11 and earlier. Update the OS if the phone supports it, or use another method |
| Unexpected push request | Deny it, report it as suspicious and change your password |
If none of these work, an administrator can reactivate Duo Mobile for the user.
How we help
We plan Duo Mobile roll-outs, write branded step-by-step user guides for enrolment and new phones, and can act as your Duo help desk for reactivations and lost devices. For staff who cannot use a phone, we supply tokens and keys. Contact us for help with Duo Mobile.
How Forever Systems supplies and supports Cisco Duo
We supply, set up and support Cisco Duo for UK organisations, from small teams and schools to multi-site businesses.
- Edition selection: Duo Free, Essentials, Advantage or Premier, matched to your users, applications and compliance needs
- Integration design: Microsoft 365 and Entra ID, Google Workspace, AWS, VPNs and firewalls, Windows and macOS logon, RDP and RD Gateway, the Authentication Proxy and Duo Single Sign-On
- Device trust: Trusted Endpoints, device health policies and Duo Desktop, alongside your MDM
- Roll-out: user enrolment, communications, hardware tokens for staff without smartphones, and help desk processes that stop MFA fatigue
- Ongoing support: policy tuning, reporting, Cyber Essentials and cyber insurance evidence, renewals and licence changes
Forever Systems Ltd is an independent IT and cyber security provider and also supplies the wider Cisco Secure portfolio.
Want a Cisco Duo quote, trial or roll-out plan?
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Contact usFrequently asked questions
Is the Duo Mobile app free?
Yes. Duo Mobile is free to download from the Apple App Store and Google Play. Your organisation's Duo subscription covers its use for work logins.
How do I move Duo Mobile to a new phone?
If your organisation has enabled Duo Mobile Instant Restore and you have a backup on the same platform (iOS to iOS or Android to Android), restore your new phone from that backup and open Duo Mobile. Otherwise, add the new phone through Duo's self-service device management or ask your IT team for a new activation link.
Why is Duo Mobile not sending push notifications?
Usually because notifications are switched off, the phone has no data connection, or its clock is wrong. Allow notifications, check the connection, set the date and time to automatic, and update the app. A passcode from the app works in the meantime.
Does Duo Mobile work without internet?
Push needs a connection, but Duo Mobile passcodes are generated on the phone and work with no signal or Wi-Fi, where your administrator allows that method.
What phones does Duo Mobile support?
The current Duo Mobile app needs iOS or iPadOS 17 or later, or Android 12 or later. Older versions have been removed from the app stores, so users on older phones need to update or use another method.
Can I use Duo Mobile for my personal accounts?
Yes. Duo Mobile can store time-based codes for other services that support authenticator apps. Back them up with Duo Restore and a recovery password, or you may need to set them up again on a new phone.