Hello @Amir Administrator
Based on your description you see a mobile number for a user in Entra ID but not in your on-premises Active Directory (AD), it usually means the attribute is out of sync or has been edited directly in Azure AD. This creates a mismatch where Azure AD becomes the authoritative source for that attribute, and changes in on-prem AD will no longer sync to Azure AD for the mobile number.
Where to Find the Mobile Number in AD
In on-premises Active Directory, the mobile number is stored in the "mobile" attribute of the user object.
You can view or edit this attribute using:
Active Directory Users and Computers (ADUC): Open the user’s properties, go to the "Telephones" tab, and look for the "Mobile" field.
PowerShell: Use Get-AD User
with the -Properties Mobile Phone
parameter to view it
To delete the mobile number for a user in on-prem AD:
Open ADUC and Select the user Right click and select properties then go to general tab you can see the telephone option you can remove the number and click on apply it will save.
PowerShell: Use Set-AD User -Identity username -Clear mobile.
I hope this information is helpful. Please feel free to reach out if you have any further questions.
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