ICT Services 4 Education


Multi-Factor Authentication on Office 365 Help



Setting up MFA


Which contact method should I use?

As detailed on our setup guide 'Setting up Multi-Factor Authentication on Office 365', in most cases you will now need to use the Microsoft Authenticator mobile app which is the recommended MFA method. It is also possible to add additional MFA authentication methods via the 'Security Info' section of 'My Account' which is detailed in the following section of the guide: 'Changing your MFA choices' . You can add a mobile number to receive a text authentication code or if you have a direct dial landline number you can also configure MFA to call this number. However, please be aware that many school phone systems may have trouble with this method because of either the automated answering attendant which some schools have, or the security on some school phone systems which stops the # key being accepted when these authentication calls come in. We have also heard of instances where spam-call-rejection features reject the authentication call.

It is also worth mentioning that you may be able to use a third party application instead of the Microsoft Authenticator app. Some of these authenticator applications will run on a desktop or laptop computer.


Using desktop authentication apps. 

If you can't use the Microsoft Authenticator on a mobile phone then an alternative option is to use a desktop authentication application. The one we have tested is called WinAuth. Our technical team have produced the following guide: 

How to set up WinAuth for Microsoft 365 MFA

Another option for Windows 10 users is WinOTP from https://apps.microsoft.com/store/detail/winotp-authenticator/9NF2RGQKX1MV?hl=en-gb&gl=gb

Please note, if you need hands on help with installing and setting up these applications then you may need to speak to your local technician.

I share this account with someone else. How do we both set up MFA on the account?

You can set up more than one Authenticator app as a method of authentication on your O365 account.  Setup MFA for yourself and then, with another user present, follow the guidance on 'Changing your MFA choices'  to setup an additional 'Authenticator App' instance which will enable the additional user to complete MFA using the Authenticator app on their mobile phone. 


Problems signing on to your account via Outlook on the web after setting up MFA

I am using the authenticator app on my phone but don't have my phone with me today. I am being asked to authenticate via the app when I log in. What do I do?

If you have set up an alternative method of completing the MFA check such as a call to your office phone then you can select "Sign in another way" and choose this option. If you don't have an alternative method set up which doesn't rely on your phone for authentication then you will need to contact your O365 administrator, usually via your headteacher, and request that the MFA on your account is reset. Once your MFA has been reset, you will be able to setup a new method of authentication which will enable you sign in to your account. 

Other issues

What if I switch mobile phone or mobile phone number?

Simply follow the instructions for 'Changing your MFA choices', but please note that you will need one of your current authentication methods set up on your account to be working so you can sign in to your account and access these options. Typically most smartphones will continue to function even if you have swapped the SIM out and in to a new phone, although you may need to select the option “I can't use my Microsoft Authenticator app right now” and then select  “use a verification code”. You will need to start the Microsoft Authenticator on your old phone, select the account, and look for the “one time password code” and type it in. Please note that this code changes every minute.

If you no longer have access to your old phone or phone number you will need to contact your O365 administrator, usually via your headteacher, to request for MFA be reset on your account which will then enable you to setup a new method of authentication using your new phone/phone number.


I have received an automated call from Microsoft asking me to press # to allow login to an account, but I am not having a problem logging in. Should I press #?

No.  If you or your school are receiving automated calls to authorise logon to an account via MFA but do not know who is triggering this request, please do not press #. If the issue persists, please let us know as this may indicate that your password has been compromised and needs changing.