Find Sms Auth Phone Number

Find the user associated with a specific SMS-based authentication phone number

Description

This runbook searches for which user has a specific phone number registered with SMS Sign-In enabled in Microsoft Entra ID. Unlike regular phone MFA methods, SMS Sign-In numbers must be unique across the tenant. If a number is reserved for SMS Sign-In by one user, assigning it to another user will fail with a "phoneNumberNotUnique" error. Regular phone MFA methods do not enforce uniqueness. This runbook helps administrators identify which user holds a specific SMS Sign-In number for troubleshooting and remediation.

Location

Organization → Security → Find SMS Auth Phone Number

Full Runbook name

rjgit-org_security_find-SMS-auth-phone-number

Details

Property	Value
Version	1.3.0
Required modules	RealmJoin.RunbookHelper (>= 0.8.9) Microsoft.Graph.Authentication (>= 2.39.0)
Schedulable	no

Permissions

Application permissions

• Type: Microsoft Graph

  • AuditLog.Read.All

    • Queries userRegistrationDetails to pre-filter users with a registered mobile phone method
  • User.Read.All

    • Reads the matched user's accountEnabled state for the report
  • UserAuthenticationMethod.Read.All

    • Batch-reads the users' phoneMethods to compare numbers and check the SMS sign-in state

Parameters

PhoneNumber

Phone number to search for in E.164 format (e.g., [phone]). The number must start with a "+" followed by the country code and subscriber number.

Property	Value
Required	true
Default Value
Type	String
Portal display name	Phone Number (E.164 format)

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