Sole global admin locked out: Authenticator push not arriving (error 500121)

Andreas Suter 0 Reputation points
2026-10-15T07:27:12.12+00:00

I am the sole Global Administrator of a Microsoft 365 business tenant and I am locked out due to MFA: the Microsoft Authenticator request no longer arrives, and no other method is registered. Because I cannot sign in, I am unable to open a ticket in the admin center, and creating a trial tenant did not work.

Error Code: 500121
Request Id: [Moderator note: Personally Identifiable Information removed]
Correlation Id: [Moderator note: Personally Identifiable Information removed]
Timestamp: 2026-10-15T06:37:31Z

Microsoft 365 and Office | Subscription, account, billing | For business | Other
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  1. Nam-D 4,410 Reputation points Microsoft External Staff Moderator
    2026-10-15T10:05:57.7233333+00:00

    Hello @Andreas Suter,

    Thank you for providing the details. I understand that you are the sole Global Administrator of your Microsoft 365 business tenant and are unable to sign in because Microsoft Authenticator notifications are not arriving, resulting in error 500121.

    In this situation, there is no supported self-service method to bypass or reset MFA from within the affected tenant. Since no additional administrator or alternative authentication method is available, the recommended recovery path is to contact Microsoft Support and request escalation to the Data Protection Team (DPT) for tenant ownership verification and MFA recovery assistance 

    Please follow these steps:

    1. Contact Microsoft Support by phone: Visit Customer service phone numbers – Microsoft Support to find the appropriate support number for your region.
    2. Explain your situation: Inform the support agent that you are the sole Global Administrator and are completely locked out of your Microsoft 365 business tenant due to an MFA issue.
    3. Request a support ticket: Ask the agent to create a service request for the affected tenant and escalate it to the Data Protection Team for ownership verification and assistance with MFA recovery.

    To help you navigate the automated phone system (IVR), you can use the following responses as a guide:

    • What kind of problem are you experiencing? Admin account locked.
    • What kind of product do you use? Office 365 for business.
    • Is it for education or business? For business.
    • Are you an administrator? Yes.
    • Do you have another administrator in your organization? No.
    • Do you need a service request? Yes.

    Once connected to a live support agent, explain that you cannot access the admin center to open a ticket and request escalation to the Data Protection Team. 

    Please note that the support team may need to verify your identity and tenant ownership before assisting with account recovery.

    I hope these steps help you regain access to your tenant.

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