Do Meeting Room Mailboxes Need a Licence in Microsoft 365?
No. A room mailbox is free, so a "Boardroom" user with a full licence is a monthly charge for a calendar. How room booking works, how to convert the account safely, and when a Teams Rooms licence is genuinely needed.
Somewhere in your user list there may be an account called Boardroom. It was created so the room could be added to Outlook invites, it was given the same licence as everyone else, and it has renewed every month since. It never needed one. Microsoft 365 has a dedicated mailbox type for rooms, and another for bookable equipment, and Microsoft doesn’t require a licence for either. The fix is to convert the account into a proper room mailbox, in the right order, and then stop paying for the seat.
A licence only enters the picture when there is hardware in the room that signs in to Teams. More on that further down.
What a room mailbox is
A room mailbox is a resource mailbox tied to a physical space. Its sibling, the equipment mailbox, is for things that move: a projector, a pool car, a van. People add either one to a meeting invitation as if it were an attendee, and it answers for itself.
An unlicensed resource mailbox is capped at 50 GB, which a calendar will never approach. Nobody needs to sign in to it, and Microsoft advises blocking sign-in on room and equipment mailboxes. New ones are created in the Microsoft 365 admin centre under Resources > Rooms & equipment.
How booking works
Out of the box, a new room mailbox behaves sensibly:
- a request for a free slot is accepted automatically, and a clash is declined;
- repeating meetings are allowed;
- the room can be booked up to 180 days ahead, for up to 24 hours at a time, and requests outside those limits are declined.
You can tighten any of that. Bookings can be limited to working hours. Requests can go to one or more booking delegates, such as the office manager, for approval instead; with several delegates, only one needs to act. Or the room can auto-accept for a named group and turn everyone else away.
Two defaults surprise people. The room’s own calendar replaces each meeting’s title with the organiser’s name, which keeps confidential subjects private but puzzles anyone checking the room calendar. And a room mailbox rejects meeting requests from outside your organisation, including a client’s invitation that a member of staff forwards to the room. An administrator can change both.
Converting the licensed “Boardroom” user
Order matters, because removing the licence from an ordinary user mailbox starts a 30-day clock, after which Microsoft deletes the mailbox data.
- Check whether anything signs in as Boardroom. Look for a PC under the meeting-room screen or a tablet by the door. If something does, read the Teams Rooms section before going further.
- Rescue any ordinary email. If people have used boardroom@ as an inbox, move out what’s worth keeping. By default, a room mailbox deletes messages that aren’t about meetings.
- Convert the mailbox. An administrator changes its type to Room in Exchange Online PowerShell, using Set-Mailbox with the Type parameter. It is the same mailbox afterwards, so the address people already use keeps working.
- Switch on automatic booking. A mailbox that began life as a user may still carry the user default, which leaves requests sitting as tentative with nobody to approve them. Set the room to auto-accept, then apply whatever booking limits you want.
- Remove the licence, then block sign-in on the account. Nobody should be logging in to a room.
- Reduce the licence count on your subscription. Unassigning a licence doesn’t stop the charge; the spare seat is billed until you remove it from the subscription, and depending on your terms that may only be possible at renewal.
That last step is where the saving usually leaks away. Our guide to a Microsoft 365 licence audit explains the renewal-date trap, and running one tends to turn up more Boardrooms: a training-room user, a “Reception” account. Addresses like sales@ and info@ follow the same logic, and our piece on whether a team address needs its own licence walks through it.
When a licence is genuinely needed: Teams Rooms
A Microsoft Teams Rooms system is certified kit, with a console, camera and microphones, that lets a room join Teams meetings by itself. It signs in with the room’s resource account, and each device needs its own account carrying a Teams Rooms licence. There are two.
- Teams Rooms Basic covers the core meeting features at no additional cost for organisations that buy a certified system. You can assign up to 25, you still have to provide payment details to get them, and they can’t license a Teams panel (the small booking screen outside the door).
- Teams Rooms Pro is paid. It adds features such as dual-screen support and fuller device management, and it is required beyond 25 devices and for Teams panels.
Microsoft is also clear about what not to do. A device used as a shared meeting device in a room needs a Teams Rooms licence even if it is just a PC signed in to the ordinary Teams app, and Teams Rooms devices shouldn’t carry staff licences. So if the Boardroom account turns out to be signed in on the PC under the screen, the answer isn’t to keep paying for a user licence. It is to plan a proper room setup, which is Teams and meeting-room work rather than a licence tidy-up.
A room with a calendar, a table and no device still needs nothing. The licence follows the hardware, not the room.
Frequently asked questions
Should we set up an equipment mailbox for the pool car or the company van?
It works well, with one adjustment. Equipment mailboxes book the same way rooms do, but the default maximum booking is 24 hours, which suits a meeting and not a three-day site visit. An administrator can raise that limit or remove it, and can extend how far ahead the vehicle may be reserved, up to roughly three years. Like a room, it needs no licence.
Do we need a room list?
Probably not yet. Room lists group room mailboxes together, and Microsoft suggests them when you have more than 100 rooms or rooms spread across several buildings. A business with two meeting rooms in one office gets little from one. Open a second site and a list per building starts to earn its place. They can only be created in PowerShell, so it is a job for whoever manages your tenant.
If the room has a Teams Rooms device, does its account need a password?
Yes, because the device signs in to Microsoft 365 by itself, which makes it the exception to blocking sign-in on rooms. Microsoft requires the password on a shared Teams device account not to expire, since an expired password signs the device out until someone intervenes, so the account usually needs an exception to your password-expiry policy. Treat it as a service credential. Make it long and random, keep it in your password manager, and let as few people know it as possible.
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