Convert a mailbox
Converting a mailbox to a different type of mailbox is very similar to the experience in earlier versions of Exchange. You must still use the Set-Mailbox cmdlet in Exchange Online PowerShell to do the conversion.
You can convert the following mailboxes from one type to another:
User mailbox to resource (room or equipment) mailbox
Shared mailbox to user mailbox
Shared mailbox to resource mailbox
Resource mailbox to user mailbox
Resource mailbox to shared mailbox
Note that if your organization uses a hybrid Exchange environment, you need to manage your mailboxes by using the on-premises Exchange management tools. To convert a mailbox in a hybrid environment, you might need to move the mailbox back to on-premises Exchange, convert the mailbox type, and then move it back to Microsoft 365 or Office 365.
If you are converting a user mailbox to a shared mailbox, you should either remove any mobile devices from the mailbox before the conversion, or you should block mobile access to the mailbox after the conversion. This is because once the mailbox is converted to a shared mailbox, mobile functionality will not work properly. Additionally, if you are trying to prevent access to the converted mailbox, you might have to reset the password. For more information on blocking access, see Remove a former employee.
Delegated Access Permission (DAP) partners with Administer On Behalf Of (AOBO) permissions can't use the procedures in this topic to convert customer mailboxes. Only members of the Organization Management role group in Exchange Online (global admins) can convert mailboxes.
Use Exchange Online PowerShell to convert a mailbox
Estimated time to complete: 5 minutes.
You need to be assigned permissions before you can perform this procedure or procedures. To see what permissions you need, see the "Recipients" entry in the Feature permissions in Exchange Online topic.
This example converts the shared mailbox, MarketingDept1 to a user mailbox.
Set-Mailbox MarketingDept1 -Type Regular
You can use the following values for the Type parameter:
For detailed syntax and parameter information, see Set-Mailbox.
How do you know this worked?
To verify that you have successfully converted the mailbox, run the following command in Exchange Online PowerShell:
Get-Mailbox -Identity MarketingDept1 | Format-List RecipientTypeDetails
The value for RecipientTypeDetails should be
For detailed syntax and parameter information, see Get-Mailbox.