This documentation provides instructions for removing SMS and Voice Call authentication methods on your account via the Microsoft My Sign-Ins portal (go/mfasetup).
Relying on telephony (SMS and Voice) is increasingly discouraged due to vulnerabilities like SIM swapping. Transitioning to phishing-resistant methods like FIDO2 security keys (e.g., YubiKey and Microsoft Passkey) significantly hardens your security posture.
1. Understanding Verification Redundancy
Microsoft Entra ID typically requires a minimum of two active authentication methods.
If you attempt to remove a phone number without having a secondary backup method in place, the system will generate recurring "Keep your account secure" prompts during the sign-in process. To suppress these prompts, you must ensure a valid secondary method—such as a Email or Security Questions—is registered before removing your phone number. *Note that both Email and Security Questions cannot be used to authenticate during sign-in. They can only be used for Self-Service Password Reset.
2. Configuration Steps
Follow these steps to update your security profile at mysignins.microsoft.com/security-info (go/mfasetup).
Step 1: Establish a Secondary Authentication Method
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Select + Add sign-in method.
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If "Email" is available: Select it and enter a non-Middlebury email address. Follow the prompts to verify the address via the sent code.
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If "Email" is unavailable: Select Security questions. Complete the required fields with memorable, secure answers and select Done.
Step 2: Update the Default Sign-in Method
You cannot delete a method that is currently set as your primary sign-in option. If SMS/Voice is set as your primary authentication option, it must be changed.
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Locate the Default sign-in method heading at the top of the page.
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Select Change.
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Set the default to Microsoft Authenticator or Passkey.
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Select Confirm.
Step 3: Remove Phone and Voice Methods
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Locate the entries for Phone, Alternate Phone, or Office Phone in the list of registered methods.
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Select Delete for each telephony-based entry.
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Confirm the deletion when prompted.