Microsoft 365
Set up multi-factor authentication (MFA)
Register the authenticator app, add a backup method, and what to do when you get a new phone.
Last reviewed 20 August 2026
MFA is the single most effective thing you can do to protect a business mailbox. A stolen password on its own then gets an attacker nowhere.
- 1Install Microsoft Authenticator from the App Store or Google Play on your phone.
- 2On a computer, go to aka.ms/mfasetup and sign in with your work account.
- 3Choose 'Add sign-in method' and select Authenticator app.
- 4Scan the QR code shown on the computer with the app.
- 5Approve the test prompt.
- 6Add a second method — your mobile number — so you're not locked out if you lose the phone.
Getting a new phone
Set the new phone up before you wipe the old one if you possibly can. Add the authenticator on the new device, confirm it works, then remove the old entry. If the old phone has already gone, contact us and we'll reset your methods after verifying who you are.
Never approve a prompt you didn't trigger. Repeated unexpected prompts mean someone has your password — deny them and phone us straight away.
Still stuck?
Log it with the helpdesk and a real engineer will pick it up — or book a call if you'd rather talk it through.