Authenticator App New Phone

Question

Hi,

I am unable to use my old phone and did not transfer the Authenticator app.

I am no longer able to sign into my account without using the code (assumed being sent to my old phone)

How can I sign into my new phone?

Thanks

Answer 1

Dear @YK,

Please understand that this forum is a public platform, and moderators will modify your question to cover your personal information in the description. Please notice to hide these personal or organization information next time you post error or some information to protect personal data. 

Based on your description, you cannot sign into your account after changing to new phone.

Since your account is a business account, your company IT team or Helpdesk may be able to reset your Multi-Factor Authentication (MFA) settings. This will allow you to reconfigure MFA from scratch on your new device. As a forum user, I do not have administrative access to change these settings. Only your IT team has the ability to adjust or reset your MFA configuration. You can also refer to this Microsoft support article for more information: Manage authentication methods - Microsoft Entra ID | Microsoft Learn  

In case you are the only Global Administrator and you are completely locked out from the tenant. You might need to contact Microsoft Support team via phone service number: Customer service phone numbers - Microsoft Support. The agent will be able to create a ticket for you under the affected tenant and then transfer this ticket to Data Protection team who could help you to regain access.   

To help you navigate the automated phone system (IVR), here's an example of what the conversation might look like:

IVR: What kind of problem are you worried about?

You: Admin account locked

IVR: What kind of product do you use?

You: Office 365 for business

IVR: Does it count for education or business?

You: For Business

IVR: Are you an admin?

You: Yes

IVR: Do you have another administrator in your organization?

You: No

IVR: Need a service request?

You: Yes

This should help you connect with a live support agent who can help you directly.

If you can't create a support ticket during the call, I recommend creating a temporary tenant account and submitting the support request from there. To create a new tenant, follow these steps:

1. Visit Office 365 E3 - Enterprise Collaboration and Productivity | Microsoft    
2. Select any plan and click Try for free.    
3. Complete the setup to create a new tenant.    
4. Ticket support: In the Microsoft 365 admin center>support>help & support. You can create a support ticket: https://admin.microsoft.com/#/support/requests     

Important: Please remember to cancel the trial subscription once your issue is resolved to avoid any charges.

I understand that this issue may take some time to resolve and could impact your workflow. However, the following solutions have been effective in resolving Microsoft Authenticator issues.

If you have any other questions, please feel free to reach out.

---

If the answer is helpful, please click "Yes". If you have extra questions about this answer, please click "Comment".   

Note: Please follow the steps in the forum documentation to enable e-mail notifications if you want to receive the related email notification for this thread. 

Answer 2

Error Code: 500121

Request Id: [Moderator note: Personally Identifiable Information removed]

Correlation Id: [Moderator note: Personally Identifiable Information removed]

Timestamp: 2026-08-06T02:03:28Z