Multi Factor Authentication code

Microsoft Authenticator and other TOTP-based apps decide whether a code is 6 or 8 digits based on how the account was originally configured by the service (issuer). The number of digits is part of the secret configuration stored on the server side and cannot be changed from the app.

If an account in Microsoft Authenticator is showing 8‑digit codes, there is no supported way in the app or in Microsoft account/Microsoft Entra settings (from the provided context) to switch that same registration to 6 digits. To use 6‑digit codes, the service that requires MFA would need to support and issue a new 6‑digit TOTP configuration, which typically means re-registering MFA for that account according to the service’s own process.

In the Microsoft ecosystem, when MFA registration is stuck or misconfigured, the supported path is to reset MFA registration (for example, via an admin using “Require re-register multifactor authentication” in Microsoft Entra ID, or via Microsoft Data Protection support if no admin access is available), then set up MFA again. However, the context only describes resetting/re-registering MFA, not changing the TOTP length itself.

So, with the information available, the code length (6 vs 8 digits) cannot be changed directly; a new MFA configuration from the service would be required, and the context does not document an option to force 6‑digit codes.

References:

• What is: Multifactor Authentication
• Set up your Microsoft 365 sign-in for multi-factor authentication
• Microsoft Authenticator app doesn't show 6-digit OTP code - Microsoft Q&A
• Reset Personal Azure MFA - Microsoft Q&A
• Global Admin Locked out - Microsoft Q&A