Global Admin locked out after iPhone replacement – Authenticator MFA cannot be re-registered

Vincent Murphy 20 Reputation points
2026-09-24T16:18:43.7766667+00:00

I am a Global Administrator for a Microsoft 365 business tenant using the domain tili2.com.

I recently replaced my iPhone, and the Microsoft Authenticator registration for my admin account did not transfer to the new device. I now cannot access Microsoft 365 Admin Center or Entra Admin Center.

After entering my password, Microsoft only offers these MFA methods:

  • Approve through Microsoft Authenticator
  • Approve through Outlook mobile
  • Enter a code from Microsoft Authenticator

None are usable because Authenticator has not yet been re-registered on the replacement phone, and Outlook is not signed into the account on that phone.

Self-service password reset does work. Microsoft allows me to verify using my registered alternate email and mobile phone, complete both verification steps, and set a new password. However, immediately afterward I am still presented with the inaccessible Authenticator/Outlook MFA methods.

I have tried Microsoft phone support. The automated system redirected me to aka.ms/prosupport and disconnected the call. I also tried creating a temporary Microsoft 365 tenant to open a support request, but that account is currently under Microsoft review.

I need assistance recovering access to the tenant and resetting/re-registering the MFA methods for the affected Global Administrator account. If this requires Data Protection / Tenant Recovery escalation, please advise or assist with that process.

I can privately provide proof of domain ownership, subscription/billing information, tenant details, and other ownership verification information as required.

Microsoft 365 and Office | Subscription, account, billing | For business | Other
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Answer accepted by question author
Ruby Nguyen 2,800 Reputation points Independent Advisor
2026-09-24T17:26:55.15+00:00

Good day Vincent and I’m sorry to hear that you are unable to access your admin account. 

Just to gently clarify before going any further, this forum is separate from Microsoft Support. I don't have access to individual accounts, nor can I investigate issues or escalate cases directly to Microsoft Support.

Changing to a new phone often triggers this issue because your Multi-Factor Authentication (MFA) settings usually need to be reset. When you switch devices or reinstall the Microsoft Authenticator app, your new phone isn’t automatically configured for authentication. Since the app is still tied to your previous device, you’re unable to receive authentication codes on the new one, which is why you can’t access your account right now. Although Self Service Password Reset allows you to change your password, it does not reset or update your existing MFA methods, so access remains blocked. 

I understand that you have tried contacting Microsoft Support without success. However, please try the example scripts below to help ensure your request is directed to the appropriate team. 

You can find the Microsoft Support phone number for your region here: Customer service phone numbers - Microsoft Support 

Tips for navigating the IVR:  

(When you call the support number, you may hear an introduction of about 30 seconds such as "you can visit the link...". You can ignore this introduction and wait until you are presented with the options. Then press "1" as a business email user, and again "1" for technical help.)    

In some countries, an automated voice system is used. Example of a dialogue: 

IVR: What problem is bothering you? 

Client: Lost access to the only admin account. 

IVR: What product do you use? 

Customer: Office 365 for business. 

IVR: School or Business account? 

Client: Business account 

IVR: Are you an administrator? 

Client: Yes. 

IVR: Is there another administrator in your organization? 

Client: No. I am the only admin in my tenant.     

IVR: Do you need to create a support ticket? 

Client: Yes. I need to create a ticket. Please send me direct to the Data Protection team. 

If you still cannot reach Support by phone and your trial tenant is currently under review, please wait for the review process to be completed. New trial tenants typically require 24 to 48 hours for verification and review. Once you can access the trial tenant, create a support request from Microsoft 365 admin center > Support > Help & Support to contact the Data Protection team regarding the previous tenant. 

Please remember to cancel the trial subscription after your issue is resolved, as this will help you avoid any accidental billing. You may prefer the following resource for detailed instructions: Cancel your Microsoft business subscription in the Microsoft 365 admin center | Microsoft Learn 

I wish I could help more directly, but as a fellow user in this community, providing these steps is the best support I can offer. I hope you're able to connect with Microsoft Support soon. 

If you have any questions, please don’t hesitate to reach out at any time. 

If you have any extra questions about this answer, please click "Comment".            

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