Use the New-UnifiedGroup Cmdlet to Create Microsoft 365 Groups with Multiple Users

Confusion About How to Add Multiple Users with New-UnifiedGroup

Updated 22-Dec-2023

The New-UnifiedGroup cmdlet from the Exchange Online management module creates a new Microsoft 365 Group). In the past, Microsoft’s documentation included the statement that:

“You can specify multiple owners separated by commas.“

Microsoft has since removed the statement from its documentation but the fact remains that people sometimes still need to nominate multiple owners when they create Microsoft 365 groups. This article covers how to accomplish that goal.

Creating Multiple Owners with New-UnifiedGroup

Many Exchange Online cmdlets accept an array of values as input for a parameter. If this was true for the New-UnifiedGroup cmdlet, it would mean that you could pass an array containing the names of multiple group owners when creating a new Microsoft 365 group. For example:

New-UnifiedGroup -Alias MyGroup -DisplayName "My Group" -Owner "Tony@Office365itpros.com", "Paul@Office365itpros.com"

But you can’t. PowerShell responds with:

New-UnifiedGroup: Cannot process argument transformation on parameter ‘Owner’. Cannot convert value “System.Collections.Generic.List1[System.String]” to type “Microsoft.Exchange.Configuration.Tasks.RecipientIdParameter”. Error: “Object of type ‘System.Collections.Generic.List1[System.String]’ cannot be converted to type ‘Microsoft.Exchange.Configuration.Tasks.RecipientIdParameter’.”

The error is unexpected, not only because it goes against the grain of “normal” Exchange Online cmdlet processing but also because you can pass the names of multiple members when creating a new Microsoft 365 group. It appears that the code used to create owners is different to that used for members. This is understandable in a way because before someone can be a group owner, they must first be added as a group member.

The ManagedBy Workaround

Fortunately, two simple workarounds exist. One is so-so, the other is much better. The first is to add multiple owners by specifying them in the ManagedBy parameter. Here’s an example:

New-UnifiedGroup -Alias "Banking.Ivestigations" -DisplayName "Banking Investigations" -Owner Tony.Redmond -ManagedBy Jessica.Chen, Tony.Redmond
Add-UnifiedGroupLinks -Identity "Banking.Ivestigations" -Links Jessica.Chen, Tony.Redmond -LinkType Members

You can see that I have specified both the Owner and ManagedBy parameter. If you don’t pass a value in Owner, Exchange Online sets the signed in user as the group owner along with the people specified in ManagedBy (a property inherited from distribution lists). The net result is that Exchange Online adds three group owners. However, Exchange Online doesn’t add the people specified in the ManagedBy property as group members, which is why I use the Add-UnifiedGroupLinks cmdlet to add those users after the creation of the new group. It is easy to forget this step and create a situation where you have multiple group owners who are not group members. This is acceptable to Entra ID and won’t cause an immediate problem, but it’s not the way that Microsoft 365 Groups are designed to work and that’s why I don’t recommend using this approach.

The Add-UnifiedGroupLinks Workaround

The second (and recommended) method is to create the new group with New-UnifiedGroup and then add as many owners as you want afterwards with Add-UnifiedGroupLinks. Just make sure that the people you add as owners are first added as members because a group owner has to be a member before they can be an owner. In this example, I declare the set of group owners in an array and then pass the array to the Add-UnifiedGroupLinks cmdlet:

[array]$Owners = "Ken.Bowers", "Michelle.Dubois", "Andy.Ruth", "Brian.Weakliam"
Add-UnifiedGroupLinks -Identity MyGroup -LinkType Member -Links $Owners
Add-UnifiedGroupLinks -Identity MyGroup -LinkType Owner -Links "$Owners

The values supplied to the Add-UnifiedGroupLinks cmdlet must be something that Exchange Online can resolve. This can be a mailbox alias, primary SMTP address, external directory object id (the identifier for the user’s Entra ID account) display name, or even a distinguished name.

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