There are a handful of license types for Microsoft Teams voice functionality. This seems painful, but really, it’s to your benefit – the licenses are “bundles” of features that you need for a specific function: user, auto attendant, shared lunchroom phone, etc. So, let’s dive in.

Throughout, I’ll use the full name “Microsoft Teams Room Pro” that you’d expect to see in the licensing tab of M365 Admin Center. I don’t stick formal names, but it feels like I should here if helping you find the right license.

Update: some name changes (surprise!) so I’ve updated this post.
Update2: Where you see “E5”, that same bit applies to E7.

Microsoft Teams Phone Standard

This one used to be Cloud PBX, then Phone System. It’s what gives your Teams client a dial pad, the ability to dial out and receive calls from the PBX, and a bunch of functions you’d find in a phone system – caller ID, hold music, transfer, etc. Without this license, you can only do Teams-to-Teams voice chats and meetings.

This license is included in a number of “bundles” that I spoke of. It is included in E5/A5/G5, Shared Space, Resource Account, Microsoft Teams Rooms Pro. It is not included in E3/A3/G3 and below. If you’re running 3’s as your main license and adding Teams voice functionality, it might be time to consider bumping up to 5 (and 7!).

Calling Plans

These are really a family of licenses, they get you a phone number and dial tone from Microsoft. That last bit is important. This is “Microsoft the telco, like AT&T”, not “Microsoft the company that wrote Teams”. I’m not saying here that Microsoft is two companies, I’m only trying to demonstrate that Calling Plans are a “telco” thing and not a “Teams software” thing. Calling plans come in “minutes per user/month/country”, as well as pay as you go.

If you are using Operator Connect or Direct Routing, you do not need anything in the Calling Plan family of licenses.

Microsoft Teams Shared Space

These used to be called Shared Device, and CAP or Common Area Phone before that. From the voice perspective, this is a phone that isn’t assigned to a user. Rather, it’s assigned to a place or a role, eg “Lunch Room”, “Reception Courtesy”, “Duty Chief”. It also applies to a host of other things, mostly around Microsoft Places.

Microsoft Teams Phone Resource Account

This license solves the problem of “I have an Auto Attendant, how do I assign it a phone number so people can call it? And how do I assign it a UPN so that my Teams users can click-to-call it in a Teams-to-Teams call”. Think of this as a special type of user license that is severely restricted. It can’t actually log on, it doesn’t get a mailbox or SharePoint or Intune or whatever. The sole purpose of a resource accounts is to plug a phone number and UPN into your auto attendant (or call queue, or other custom voice app) – nothing more.

A resource account is based on a user account. Microsoft had a choice: copy the user account code and massively customize it to do everything a resource account needs without a license, or craft a purpose-built license that takes care of that, without requiring the rewrite. They chose the latter. That license is the Microsoft Teams Resource Account license. It is the ONLY license that you should assign to a resource account other than adding something from the Calling Plan family, should you be using Microsoft Calling Plans for your dial tone & phone numbers. In Teams Admin Center, resource accounts have their own section apart from users. In PowerShell, you’ll mostly use “user” commandlets.

And on the plus side? The license is completely free. You obtain it the same way you do any other license, but it’s $0. You need one of these for each phone number or UPN that you want to use to enable an auto attendant, call queue, or voice app to receive phone calls. (Note: if you have an auto attendant that forwards the caller off to a call queue, but you do not want that call queue to be called directly, you need only license the auto attendant. The call queue cannot be called directly, nor does it appear in the directory in Teams).

Microsoft Teams Audio Conferencing

This license allows the user to create a Teams meeting that allows dial-in capabilities. This is old school dial-in to a conference bridge. Those who dial in do not require this license, only the meeting organizer. It also allows dial out from the meeting to a phone number to add them to the meeting. This is an add-on, but it feels like it’s bundled with an awful lot of other licenses.

Did I miss anything? Hit me up in the comments if you’d like me to add or clarify something.