How to Convert a User Mailbox to a Shared Mailbox in Exchange Online

This guide explains two methods for converting a user mailbox to a shared mailbox in Exchange Online: using the Microsoft 365 interface or PowerShell, and managing the process with CoreView.

Methods to Convert User Mailboxes to Shared Mailboxes

You can convert a user mailbox to a shared mailbox through either the Exchange Admin Center or PowerShell.

Using the Exchange Admin Center

• Sign in to the Exchange admin center.
• Navigate to Recipients > Mailboxes.
• Select the user mailbox you want to convert.
• Click “Convert to shared mailbox”.
• Confirm the conversion when prompted.

Using PowerShell to Convert User Mailboxes

• Open an Exchange Online PowerShell session.
• Run the following command:

Set-Mailbox -Identity <MailboxIdentity> -Type Shared 

• Confirm mailbox conversion.

Recommendation - Once the mailbox is converted to shared, you can remove its license if direct user access isn’t required. Removing unnecessary licenses helps optimize costs (shared mailboxes don’t require a license unless over 50GB or using in-place archive features).

For more information check the Convert a mailbox in Exchange Online article.

Using CoreView to Convert User Mailboxes

You can use CoreView to convert user mailboxes to shared mailboxes in bulk or individually.  

• Go to the CoreView app.
• Select ACTIONS > Management Actions > Mailbox > Convert to shared mailbox.

• Select one or more user mailbox(es) or upload a CSV file with the list of targets.
• Click Continue > Proceed.
• Optionally, enter notes (such as a ServiceNow ticket number or the reason for the change) for audit and tracking purposes in CoreView.
• The selected mailboxes are converted to shared mailboxes.

Operators can only view and manage mailboxes within their assigned V-Tenant scope.