How to assign a license to a shared mailbox in the Exchange Admin Center with the 2025 interface?

Question

Hello,

I would like to assign a license (for example, Office 365 E3) to a shared mailbox in the Outlook admin center in order to:

• Exceed the 50 GB storage limit
• Enable Exchange Online archiving

Do you have a solution for this?
Thank you in advance for your help!

Answer 1

Dear Sarah, 

Thank you for reaching out to Microsoft Community regarding your shared mailbox configuration in Microsoft 365. I understand you’d like to assign a license such as an Office 365 E3 plan to a shared mailbox in order to exceed the 50 GB storage limit and enable Exchange Online Archiving. I’m happy to help. 

Please try the following steps to Assign a License via Microsoft 365 Admin Center 

1. Sign in to the Microsoft 365 Admin Center.
2. Go to Users > Active users.
3. Search for and select the user object associated with your shared mailbox. If the mailbox was created as a shared mailbox from the start, it still has a user account associated with it.
4. Click on Licenses and apps.
5. Choose the license you wish to assign (e.g., Office 365 E3) and confirm your selections.
6. Click Save changes.

If you're unable to locate the shared mailbox in Active users, it may need to be temporarily converted to a regular user mailbox: > - Go to Exchange Admin Center > Recipients > Mailboxes. > - Select the shared mailbox and choose Convert to regular mailbox. > - Assign the license. > - Once configured, you may reconvert it back to a shared mailbox. 

NOTE

• Archiving Activation: After licensing, it may take a few hours for the Archive mailbox option to appear under the mailbox properties in the Exchange Admin Center.

Please let us know if you need further clarification or assistance. We appreciate your patience and look forward to assisting you further.  

We hope you have a great day! 

Warm Regards,     

Chris-DKN - MSFT | Microsoft Community Support Specialist.