I don't have access to my old phone to receive codes

Dear @kizzy thomas01,
Thank you for posting your question in the Microsoft Q&A forum. I understand you recently lost your old phone, moved your data to a new phone, and now your school website sign-in is still sending Microsoft Authenticator verification prompts/codes to the old device, so you can’t complete sign-in.

This typically happens because the MFA (multi-factor authentication) method is still registered to the previous phone. Even if you transfer phone data, a work/school account in Microsoft Authenticator often needs to be re-registered on the new device, and the old method should only be removed after the new one is working.

Could you please confirm if you are using a personal account (@outlook.com/@hotmail.com email), or is it a work/school account (e.g., @company.com)? 

Option 1: If you are user or have other admins in your organization, to regain access to your account, I recommend you contact your IT admin/Global admin to raise a request for resetting your authentication method in the Entra admin center. Admin can revoke MFA sessions and require re-registration in Microsoft Entra admin center.

For step-by-step details, refer to the official Microsoft documentation: Manage authentication methods for Microsoft Entra multifactor authentication - Microsoft Entra ID | Microsoft Learn  

Option 2: If you are the only Global Administrator and you are completely locked out from the tenant, for access to the administrator account, please contact the Data Protection Team directly. Contacting Microsoft Data Protection team by phone support - Customer service phone numbers - Microsoft Support.

Microsoft Data Protection team has only required permission to reset your account on the backend. They are the only responsible and privileged support team for account questions.

During the phone call, you will be required to provide the information associated with your subscription - such as your company name, billing details, phone number, and alternate email address - to verify ownership of the company’s tenant. This verification will assist the Data Protection Team in granting you access to the administrator account.

Please carefully follow this instruction to ask for Microsoft Data Protection team support:   

• Depending on your country or region. For some countries, when calling the support number, although there are about 30 seconds opening as something "you can visit the link...." But you can ignore this opening and wait until the option, then "1" as a business email user, "1" again for technical help.
• For some countries, it will be an automated conversation like:
• First, when you call the hotline, it asks what kind of problem you are worried about.    Answered: authenticator.
• A: What kind of product are you using?
• B: Office 365 for business.
• A confirmation: education or company account?
• B: For companies
• A: Are you an administrator?
• B: Yes.
• A: Do you have the other admin in your organization?
• B: No.
• A: You need one.... Service request?
• B: Yes

In this situation, only Microsoft Data Protection team has tools and processes in place to verify identity and regain access to administrator accounts.     

If your organization's Office 365 Business/Education subscription is from a partner or reseller, and the global administrator is unable to open a service request on your end, contact the reseller's support provider to help open a service request on behalf of you instead.   

Please understand that forum moderators have no control over user accounts, especially when it comes to logging in to your account, resetting your password, changing your access, etc.   

Alternatively, you can try set up a new trial tenant and submit your support request: 

1. Start a free trial: Go to Compare Office 365 Enterprise Pricing and Plans | Microsoft 365.  and click Try for free to create a new tenant.
2. Complete setup: Follow the guided steps to create a new Microsoft account and tenant.
3. Access Admin Center: Sign in at https://admin.microsoft.com.
4. Open Support: In the left menu, select Support > Help & support.
5. Submit a ticket: Clearly state you are locked out of a different tenant where you are the admin. Include: Admin account email, Tenant domain name, Error messages, Issue details, Confirmation you are the administrator
6. Track your request: Submit and note the ticket number.

Important notes:  

• The trial tenant won’t give access to your original tenant’s data or settings; it’s only for contacting Microsoft support.
• Support may require identity and admin rights verification for the locked tenant.
• Resolution could take longer because you’re contacting from a different tenant.
• Please do not forget cancel the trial subscription after resolving the issue to avoid charges (Admin Center > Billing > Your products).

I truly appreciate your patience and understanding. If you have any further questions or need further clarification, please feel free to reach out. I'm looking forward to hearing from you. 

Thank you for your cooperation.

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Hello,

Microsoft does not directly manage organization users. Instead, each organization's IT administrator is responsible for managing its users according to its internal protocols.

You should contact your organization's IT support team. They need to reset your MFA for you in order for this to work. Once the reset is completed, follow these steps:

1. Open your web browser and navigate to https://login.microsoftonline.com.
2. Sign in to your account.
3. You will be prompted to set up MFA again. Make sure to update your phone number during this process.

If your organization's IT administrator requires guidance, they can follow these steps:

1. Sign in to the Microsoft Admin Center at https://admin.microsoft.com using their credentials.
2. Navigate to Users > Active Users in the left-hand menu.
3. Select the relevant user.
4. On the user card that appears on the right, scroll to the bottom and click Manage multifactor authentication.
5. On the MFA settings page, locate the user's name, select it, and click Manage user settings on the right.
6. In the pop-up box, check the first box and click Save.

This process will reset MFA for the user, allowing them to set it up again.