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Duo Application

Duo Mobile

Use this guide when Duo Mobile is not approving sign-ins after a new phone, you are not getting Duo pushes, or you need to reactivate Duo Mobile after reinstalling it.

Reviewed April 2026

Application Guide

Overview

Duo Mobile is the second-factor app many companies use to approve sign-ins, with push approvals, passcodes, and (in some setups) hardware-style codes.

Most Duo tickets are 'I got a new phone' and the fix is a Duo support team reset plus a fresh enrollment link, not reinstalling the app.

Plain English

What this app is usually used for

Mobile multi-factor authentication app used for Duo-protected sign-ins, push approvals, and time-based passcodes.

It is part of the Duo family covered in our app help.

Common problems

Common problems

I got a new phone and Duo isn't working

You have a new phone and pushes from Duo Mobile do not let you sign in.

Likely fix

Contact IT to verify your identity and either send you a fresh Duo enrollment link or have you use the self-service Duo portal if your firm has one.

What to collect

Send your name, your new phone model, and the apps you are blocked from signing into.

I'm not getting Duo pushes

Duo Mobile is installed and enrolled, but no approval push arrives.

Likely fix

Check notification permissions for Duo Mobile in your phone settings, confirm internet connectivity, and use the refresh option in Duo Mobile.

What to collect

Send the phone OS and version, the Duo Mobile version, and whether notifications are enabled for Duo Mobile.

Reinstalled Duo Mobile and lost my accounts

You reinstalled Duo Mobile on the same phone and your accounts are gone.

Likely fix

If your firm enabled Duo Restore before, restore from Duo backup; otherwise IT can send a new enrollment link.

What to collect

Send your phone model and whether you had Duo Restore enabled.

First things to try

First things to try

Quick checks before you change anything

  • Is this a new enrollment, a phone replacement, or a reactivation on the same phone after reinstalling?
  • Do you still have your old phone, and does it still receive Duo pushes?
  • Does your company use a self-service Duo portal where you can re-enroll yourself?
  • Which work apps are you trying to sign into when Duo blocks you?

Try these fixes first

  • If you still have the old phone, keep it nearby — IT may be able to use it to verify you.
  • Check that notifications are enabled for Duo Mobile in your phone settings — pushes will not arrive otherwise.
  • If your company has a self-service Duo portal, try that before contacting IT.

Slow down

Do not do this yet / warnings

Avoid these until support says it is safe

  • Before removing Duo Mobile, confirm another approved sign-in method exists, and have the support team clear the out of date device from Duo if the phone is being replaced.

What support needs

What details support needs

Send these details

  • A note about whether you still have the old phone.
  • Your phone model and OS version.
  • Whether notifications for Duo Mobile are enabled in phone settings.
  • A screenshot of the work app's Duo prompt, if you can take one.

Licensing & access

Licensing / access notes

Licensing / access checks

  • Duo Mobile is free to install — your access depends on your company's Duo subscription and your enrollment.
  • If you are switching phones, IT must verify your identity before resetting Duo to prevent account takeover.
  • A bypass code from IT can let you sign in once while you finish setting up the new phone.

More checks

More setup checks

Install / update basics

  • Install Duo Mobile from the App Store or Google Play.
  • When IT sends you a Duo enrollment link, open it on the new phone, then scan the QR code Duo shows or follow the on-screen prompts.
  • Allow notifications so push approvals can reach you.

More things to check

  • Verify the user's identity independently (HR system, manager confirmation) before resetting Duo — multi-factor sign-in reset is a common phishing target.
  • Check if the user has a registered backup method (SMS, voice call, hardware token) before wiping Duo enrollment.
  • Generate a bypass code rather than deleting enrollment when the user still holds the old phone.