Authenticator - new user

Question

Trying to get Authenticator on to an Android phone for a new user, one time password shows as 8 digits, PC is looking for 6 digits?

Answer 1

The difference in code length is expected behavior and depends on how the account was configured in Microsoft Authenticator:

• Microsoft Authenticator can generate different formats of OATH verification codes (for example, 6‑digit or 8‑digit) depending on the service and how the account was added.
• The PC sign-in page is explicitly asking for a 6‑digit OTP, so an 8‑digit code from the app will not be accepted.

To resolve this, remove and reconfigure the account in Microsoft Authenticator so that it matches the OTP format expected by the service:

1. On the PC, start the MFA setup flow again for that user (for example, via the service’s security/MFA setup page).
2. When prompted to configure an authenticator app, scan the new QR code with Microsoft Authenticator on the Android phone.
3. Complete the setup and verify that the app now shows a 6‑digit code for that account, matching what the PC sign-in page expects.
4. Use that 6‑digit code to sign in.

If the account continues to show only an 8‑digit code while the PC insists on 6 digits, the MFA profile for that user may be stuck or misconfigured. In that case, an administrator should reset the user’s MFA registration in Microsoft Entra ID and require re-registration, then repeat the setup:

1. In the Microsoft Entra admin center, go to Identity → Users → All users.
2. Select the affected user and open Authentication methods.
3. Select Require re-register MFA.
4. Have the user sign in again and re-register Microsoft Authenticator when prompted.

This forces a clean re-enrollment of the authenticator app and aligns the OTP format with what the PC expects.

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References:

• Authentication methods in Microsoft Entra ID - Microsoft Authenticator app
• Enable passwordless sign-in with Authenticator
• Troubleshoot problems with Microsoft Authenticator
• Reset Personal Azure MFA - Microsoft Q&A