comment réinitialiser le MFA sur le compte administrateur du tenant 365. Le code que je reçois comporte 8 chiffres alors qu'il m'en faut 6

Hello Francois,

Thank you for posting question on Microsoft Windows Forum.

Based on your issue description, I would like to share my thought of that the 8-digit code is probably used for passwordless sign-in, where you match a number on the screen to a number in your app. The 6-digit code is the standard Time-based One-Time Password (TOTP). Your login attempt is incorrectly requesting the 6-digit code when your app is set up for the passwordless method. You can try the below suggested solutions.

1.Use the Correct Sign-in Method (Push Notification).

1. Go to the Microsoft 365 sign-in page.
2. Enter the administrator email: ******@a2r36400.onmicrosoft.com and the password.
3. Do not click any links like "I can't use my authenticator app right now" or "Use a verification code."
4. Wait for the prompt on the sign-in screen that shows a two-digit number.
5. Check the phone with the Authenticator app. You should receive a push notification asking you to approve the sign-in.
6. Open the notification. The app will show you three two-digit numbers. Tap the number that matches the one shown on your login screen.
7. You may then be asked for your phone's biometrics (face/fingerprint) or PIN to complete the sign-in.

• This number-matching process is the intended use for the 8-digit codes you are seeing (which are actually generated behind the scenes for this verification). If it does not work. Please proceed to step 2.

2.Sign In Using Another Method (SMS Code).

1. On the MFA prompt screen, look for a link that says "Sign in another way" or "I can't use my app right now".
2. Click it. You should be presented with a list of other available verification methods.
3. Choose the option to "Text a code to my phone" which should be linked to the number ending in ****95 (0665248495)**.
4. You will receive a standard 6-digit code via SMS. Enter this code to complete the sign-in.

3.Contact Microsoft Support.

• If you cannot receive push notifications and the SMS option is not available or does not work, the account's MFA registration is likely corrupted, and you are effectively locked out. The only remaining option is to contact Microsoft's Data Protection team.
  1. Find your local Microsoft 365 for Business support phone number from this official list.
  2. Call them and explain that you are locked out of your sole tenant administrator account.
  3. They will initiate a lengthy identity verification process to prove that you are the legitimate owner of the tenant. This can involve providing domain registration details, company information, and other legal documentation.
  4. Once your ownership is verified, they can temporarily disable MFA on the account, allowing you to sign in, reset your MFA configuration properly, and create a new "break-glass" admin account.

If the above information is helpful. Free feel to hit "Accepted" for benefitting others in community having the same issue too.