What if you need to bulk update Microsoft 365 groups membership e.g. to add a group owner or member for tens of thousands m365 groups? Iterating through groups one-by-one is unproductive and could take days. Can we do it faster? Here is what I found.

In my case, it was Microsoft 365 ownerless groups policy implementation for large tenant… Skipping details – I needed to update ownership for 10,000 Microsoft 365 groups and I was looking for a best/fastest possible option maybe some kind of bulk update or with multiple threads. And I figured out that the fastest way is to use PnP.PowerShell that calls Microsoft Graph API but run it against list of groups with PowerShell parallel trick. Here is the sample PowerShell code:

$groups | ForEach-Object -Parallel {
    $owner = "newGroupOwnerUPN@contoso.com"
    Add-PnPMicrosoft365GroupOwner -Identity $_.Id -Users $owner
} -ThrottleLimit 50

That worked for me perfectly and it took ~8 seconds per 1,000 groups.