O365 - Clear Immutable IDs for all users

The following can come in handy when working on domain migrations, etc.

You can use the following command to clear the immutable ID for all Office 365 user accounts of a specified domain.

REMEMBER TEST FIRST AND USER AT YOUR OWN RISK

Set-ExecutionPolicy Unrestricted -Scope Process

$domain = Read-Host 'Please enter your domain name'

try

{

    $cred = Get-Credential

    Import-Module MSOnline

   

    Write-Host "Connecting to domain using credentials provided..."

   

    Connect-MsolService -Credential $cred

    Write-Host "Connected to domain."

           

    Write-Host "Fetching users from domain."

    $allUsers = Get-MsolUser –All -DomainName $domain | Select userPrincipalName,ImmutableId

    $totalUserCount = $allUsers.Count

    Write-Host "Fetched" $totalUserCount "users from domain."

    Write-Host "Going to clear ImmutableId property of all users who have a value."

    $count = 0

    foreach ($user in $allUsers)

    {

        try

        {

            if ($user.ImmutableID -ne "$null")

            {                   

                Set-MsolUser -UserPrincipalName $user.userPrincipalName -ImmutableId "$null"

                Write-Host "ImmutabelId cleared for user : " $user.userPrincipalName

                $count++

            }

        }

        catch

        {

            Write-Host "Error - ImmutableId could not be cleared for user : " $user.userPrincipalName

            write-host "Exception Message: $($_.Exception.Message)"

        }

    }

    Write-Host "Success - ImmutableId cleared for" $count "users."   

}

catch

{

    Write-Host "Error - Failed to run the process."

    write-host "Exception Message: $($_.Exception.Message)"

}