Sign On on a .onmicrosoft.com account without autenthicator

Question

Hello,

i lost my device with the autenthicator app.

Now i am not able to sign in to my comercial account ****.onmicrosoft.com. All alternative methodes (using a verification code) lead me to the authenthicator app, which i am not able to access.

I am able to access the account with my companies address, but here i cannot reset my onmicrosoft.com account.

What can i do?

Answer 1

Because all sign-in methods for the ****.onmicrosoft.com commercial account are currently pointing back to Microsoft Authenticator and that device is lost, the account’s MFA needs to be reset by Microsoft support or by another admin on the tenant.

Use these options depending on your situation:

1. If there is another Global Admin on the tenant
   • Ask that admin to sign in to the Microsoft 365 admin center.
   • They can reset your MFA methods for the ****.onmicrosoft.com account so a new method (new Authenticator app, SMS, etc.) can be registered.
2. If you are the only Global Admin on the tenant
   • This requires the Microsoft Data Protection team to verify identity and reset MFA.
   • Call Microsoft support using the regional customer service phone number: see Customer service phone numbers in the referenced answers.
   • When navigating the phone IVR, clearly state that this is a business/Office 365 for business/commercial tenant and that you are the only administrator locked out due to Authenticator.
   • Ask the agent to open a service request and escalate to the Data Protection team for an admin MFA reset on your ****.onmicrosoft.com account.
3. If phone support is hard to reach
   • Create a temporary trial Microsoft 365 tenant (a new, separate tenant) using a trial subscription as described in the referenced Q&A.
   • Sign in to the new tenant’s Microsoft 365 Admin Center.
   • From Help & support, open a support ticket explicitly stating that you are locked out of a different existing tenant (provide the ****.onmicrosoft.com admin UPN and tenant domain) and request Data Protection to reset MFA on that original tenant.
   • After the issue is resolved, cancel the trial subscription to avoid charges.

Until MFA is reset by support or another admin, the ****.onmicrosoft.com account cannot be recovered through self-service because all flows redirect to the lost Authenticator method.

---

References:

• Common problems with two-step verification for a work or school account
• Use a screen reader to set up and troubleshoot multifactor authentication
• I cant log in to my business account because it is requiring Authenticator app which I do not have - Microsoft Q&A
• How Do I Regain Access to My Account After Losing Access to Microsoft Authenticator? (Urgent Request). - Microsoft Q&A
• I have a Micrsoft business account and I am the admin and the only user registered under this account. I can't log in because i have replaced my phone and the authenticator doesn't work. - Microsoft Q&A
• Requesting a Tenant Admin MFA Reset - Microsoft Q&A