Request for Procedure to Authenticate Three Devices with the Same Account

Below is the supported way to use the same Microsoft Entra ID (work/school) account with Microsoft Authenticator and passkeys across multiple devices, starting from one already-initialized device.

1. Ensure the account is set up with a passkey in Microsoft Authenticator (per device)

Repeat these steps on each mobile device that should authenticate with the same account.

iOS device

1. Open Microsoft Authenticator.
2. Tap Add Account or the + button.
3. Select Work or school account.
4. Tap Sign in and complete MFA as required.
5. When prompted, select Open Settings to enable Authenticator as a passkey provider.
6. In iOS Settings, go to Passwords > Password Options.
7. Turn on Autofill Passwords and Passkeys.
8. Under Use Passwords and Passkeys From, select Authenticator.
9. Return to Authenticator and select Continue (or Done) to complete registration.

Android device

1. Open Microsoft Authenticator.
2. Tap Add Account or the + button.
3. Select Work or school account.
4. Tap Sign in and complete MFA as required.
5. On the Android device, open Settings.
6. Go to Passwords & Accounts.
7. Under Additional providers, enable Authenticator.
8. Return to Authenticator and select Done to finish setup.

Perform the above on each of the three devices using the same work/school account. This creates a passkey on each device tied to the same account and enables seamless SSO in Microsoft apps on each device.

2. Use cross-device sign-in from mobile to other devices (if needed)

If one of the three devices is a PC or other device where direct Authenticator installation is not used for sign-in, use cross-device passkey sign-in from the mobile Authenticator device:

1. On the target device (for example, Windows 11 23H2 PC), open the Microsoft app or site (such as Office) and start sign-in.
2. If prompted, choose Other ways to sign in or Sign-in options, then select Face, fingerprint, PIN, or security key.
3. On Windows 11 23H2 or later, select iPhone, iPad, or Android device.
4. A QR code appears on the screen.
5. On the iOS or Android device that has Authenticator configured for the account, open the system camera app (not the camera inside Authenticator) and scan the QR code.
6. When prompted on the phone, select Sign in with passkey.
7. Confirm with Face ID, Touch ID, fingerprint, or device PIN.
8. The target device is now signed in with the same account.

Repeat this cross-device sign-in process from any of the mobile devices already configured with Authenticator to sign in to the same account on additional devices.

After these steps, all three devices will authenticate using the same account, each with its own local passkey in Microsoft Authenticator and the ability to sign in to Microsoft Entra ID resources.

References:

• Set up a passkey in Microsoft Authenticator
• Sign in with a passkey in Microsoft Authenticator