At some point, you may want to convert a user mailbox to a shared mailbox. Perhaps as part of your Office 365 mailbox life cycle management when a user leaves your organization.
This post will show how to convert an Office 365 mailbox to a shared mailbox using any of the following tools:
- Active Directory Users & Computers (with the Easy365Manager plugin).
- The Set-Mailbox PowerShell command.
- The Exchange Admin Center.
1. Mailbox Conversion Using Active Directory Users & Computers
The easiest way to perform a mailbox conversion is using the Active Directory Users & Computers MMC.
You need to have the Easy365Manager snap-in installed to follow this procedure.
Open up user properties and go to the Mailbox tab. Here you can select any of the four mailbox types to convert the mailbox:

After converting the mailbox to a shared mailbox, you can remove the license. You can also do this using the Easy365Manager tool, as seen in the following screenshot:

Alternatively, you can use the Office 365 Admin Portal to remove the Exchange Online license.
With Easy365Manager, you can perform all daily Office 365 management directly from AD Users & Computers. Even ones that require PowerShell.
This allows you to save time and move a lot of work from senior supporters to the first-level helpdesk.
You can even get rid of your on-premises Exchange Server.
See the many Easy365Manager features here.
Download a free, fully functional 30-day trial here.
2. Mailbox Conversion Using PowerShell
Use the Set-Mailbox PowerShell command to convert your Office 365 mailbox to a shared mailbox. The below example shows you how:
Connect-ExchangeOnline
Set-Mailbox username@company.com -Type Shared
Disconnect-ExchangeOnline
Start by establishing a connection with Exchange Online (lines 1).
Convert the mailbox type using the Set-Mailbox command (line 2).
End your Exchange Online session when done (line 3). If you don’t explicitly close the session, you risk depleting the number of available sessions.
To convert your mailbox to other types than Shared, use these parameters:
- Regular (user)
- Room
- Equipment
To verify the conversion, take a look at the RecipientTypeDetails of the mailbox, e.g.:
PS C:\WINDOWS\system32> Get-Mailbox Marketing | fl Name,RecipientTypeDetails Name : Marketing RecipientTypeDetails : SharedMailbox
3. Mailbox Conversion Using the Exchange Admin Center
You can also perform mailbox type conversion using the Exchange Admin Center. To change the mailbox type, follow these steps:
Open up the Exchange Admin Center using your admin account and locate the mailbox you want to convert:

Compared with using Easy365Manager, this is not very intuitive and requires some amount of training for new IT staff.
License Considerations
A shared mailbox in Office 365 does not require a license, but you need to have your own personal mailbox (which must be licensed) to access it. Also, if you want your shared mailbox to store more than 50 GB or to have an archive, you need to license it.
Keep in mind that you shouldn’t delete the user account after converting the mailbox to a shared mailbox. The user account is still needed, although you can’t use it for logging in.