Teams Phone licensing trips people up because the name suggests it does more than it does. You buy Teams Phone, assign it, and then a user still can’t dial a mobile number — and now you’re staring at the admin center wondering what you missed. The answer is almost always the same: Teams Phone is only half the picture.
There are two separate things to license. One is the calling system itself, which gives you hold, transfer, voicemail, auto attendants, and call queues. The other is the connection to the public phone network, which is what actually lets a Teams user call an outside number. They’re sold separately and behave differently, and mixing them up is the root of most licensing confusion.
This guide untangles the layers: what Teams Phone includes, which PSTN connection options exist and how each changes what you buy, the free-but-conditional resource account license, and the order to assign everything so calling actually works.
The two layers of Teams calling
Every Teams calling setup is built from two stacked layers, and it helps to keep them mentally separate.
Layer 1 — Teams Phone (the PBX). This is the private branch exchange in the cloud. It handles call control: making and receiving calls inside your org, placing people on hold, transferring, parking, voicemail, and the service features like auto attendants and call queues. Teams Phone is what turns Teams from a meetings-and-chat app into a phone system.
Layer 2 — the PSTN connection (the outside line). Teams Phone on its own can’t reach a landline or a mobile. For that you need a path to the Public Switched Telephone Network. Microsoft gives you three ways to provide that path, and your choice here decides what you buy and where your phone numbers come from.
If you only ever needed internal calls, Layer 1 would be enough. Almost nobody does, which is why the PSTN connection matters as much as the license name everyone focuses on.
The two layers, side by side
| Teams Phone | Calling features / PBX: hold, transfer, voicemail, auto attendants, call queues, internal calls |
|---|---|
| PSTN connection | The line to the outside world: lets users dial and receive external landline and mobile numbers |
What Teams Phone actually includes
Teams Phone is the add-on (or bundled entitlement) that enables the calling system for a user. Once a user has it, they can:
- Make and receive internal calls to other voice-enabled users.
- Use core PBX features — hold, transfer, consultative transfer, call park, and forwarding.
- Have voicemail.
- Be added as an agent in a call queue or sit behind an auto attendant.
What Teams Phone does not do by itself is connect that user to the PSTN. A brand-new Teams Phone user with no calling plan or routing assigned can call colleagues all day and still get an error trying to dial a supplier’s mobile. That gap is by design — external connectivity is the second purchase.
Teams Phone is included in Microsoft 365 E5 and Office 365 E5. On E3, Business, and most lower tiers, it’s a separate add-on you buy and assign per user. Either way, the entitlement is the same calling system; the only difference is whether it’s bundled or bolted on.
The three ways to connect to the PSTN
This is the decision that shapes your whole licensing bill. Teams Phone needs a PSTN connection, and there are three routes. Each changes what you license and who supplies your numbers.
PSTN connection options
| Microsoft Calling Plan | Microsoft is your phone carrier. You buy a Calling Plan add-on with minutes; numbers come from Microsoft. Simplest, fewest moving parts. |
|---|---|
| Operator Connect | A participating carrier provides PSTN through the Teams admin center. No SBC to run; the carrier handles the trunk and often the contract you already have. |
| Direct Routing | You connect your own Session Border Controller (SBC) and carrier. Most control and often the best per-minute rates, but you run the infrastructure. |
With a Calling Plan, you license Teams Phone and a Calling Plan per user. Microsoft becomes your carrier, hands you numbers, and bills the minutes. It’s the path with the least to manage.
With Operator Connect, you still need Teams Phone per user, but the minutes and numbers come from a participating operator rather than a separate Microsoft Calling Plan SKU. There’s no SBC to deploy — the operator’s trunk shows up in your tenant.
With Direct Routing, you license Teams Phone per user and bring your own connectivity through an SBC and a carrier of your choice. There’s no Calling Plan SKU at all; your PSTN cost sits with the carrier. This is the route for organizations with existing telephony contracts or specific routing needs.
If you haven’t settled on one yet, the trade-offs are laid out in Calling Plan vs Operator Connect vs Direct Routing. The licensing follows from that choice, so decide it first.
Communication Credits and pay-per-use calling
Some calling scenarios aren’t covered by a flat plan: dialing out from a meeting to add someone by phone, toll-free numbers that you pay for inbound, or international minutes beyond what a plan includes. These have historically been funded by Communication Credits, a prepaid balance the tenant tops up.
Microsoft has been moving tenants toward Pay-As-You-Go Calling Plans for this kind of usage, but the principle hasn’t changed: you need a funding source for metered calling that a fixed plan doesn’t cover. If toll-free service or meeting dial-out suddenly stops working, an empty or unconfigured credit balance is a common cause. Check it before assuming a deeper fault.
Resource account licenses: free, but with a catch
Auto attendants and call queues don’t run on a person’s account. Each one sits on a resource account — a disabled user object that represents the service. That resource account needs its own license: the Microsoft Teams Phone Resource Account license, often called the virtual user license.
Two facts about it cause most of the confusion:
- It’s free. You don’t pay per resource account license.
- It’s conditional. The free virtual user licenses only become available once your tenant owns at least one paid Teams Phone license. No paid Teams Phone in the tenant, no free resource account licenses to assign.
So the first auto attendant in a brand-new tenant can stall: you go to assign the virtual user license and there are zero available, because nothing has unlocked them yet. Buy or assign a paid Teams Phone license somewhere in the tenant and the free pool appears.
Building those services is covered step by step in how to set up call queues in Microsoft Teams, including where this license fits in the sequence.
A worked example: what to buy for 50 users plus a main line
Say you have 50 staff who all need external calling, plus a single main business number that greets callers and routes to a support team. Here’s how the licensing stacks up, regardless of small price differences between regions:
Example: 50 users + auto attendant + call queue
| 50 × Teams Phone | Calling system for every voice user (bundled in E5, or an add-on on lower tiers) |
|---|---|
| PSTN connection for 50 users | Calling Plan per user, OR Operator Connect numbers, OR Direct Routing via your SBC |
| 1 × Resource Account license (auto attendant) | Free virtual user license — unlocked by owning paid Teams Phone above |
| 1 × Resource Account license (call queue) | Free virtual user license for the queue's resource account |
The pattern holds at any scale: one Teams Phone per human, one PSTN path per human who calls outside, and one free resource account license per auto attendant or call queue. The resource account licenses cost nothing but still have to exist and be assigned.
The order to assign licenses
Sequence matters more than people expect, because some assignments depend on others having provisioned first.
Licensing order that avoids the common failures
- Confirm each voice user has a Teams Phone license (bundled in E5, or assigned as an add-on)
- Assign the PSTN connection per user: a Calling Plan, an Operator Connect number, or a Direct Routing voice policy
- Set each user's usage location before assigning calling plans or numbers
- For services, create resource accounts and assign the free Teams Phone Resource Account license
- Let each license fully provision, then assign phone numbers
- Test internal and external calls for a real user before rolling out widely
Usage location is the quiet one. A user or resource account without a usage location set can’t be assigned a Calling Plan or, in some cases, a number — and the error message rarely points straight at it. Set it first.
Once licensing is sorted, assigning numbers to people is its own task with its own quirks; that’s walked through in how to assign phone numbers to Teams users.
Common licensing mistakes
The same handful of issues come up again and again:
- Teams Phone but no PSTN connection. The user has the calling system but no line out, so external calls fail. Assign a Calling Plan, Operator Connect number, or Direct Routing policy.
- Expecting Operator Connect or Direct Routing to replace Teams Phone. They replace the Calling Plan, not Teams Phone. You still need Teams Phone per user.
- No paid Teams Phone in the tenant, so no free resource account licenses appear. Buy or assign one paid Teams Phone license to unlock the free pool.
- Assigning a number before the license provisions. Let the license apply first, then attach the number.
- Putting a user Teams Phone license on a resource account. Resource accounts get the dedicated Resource Account license instead.
- Forgetting usage location, which blocks calling plan and number assignment.
Wrapping up
Teams Phone licensing makes sense once you stop treating “Teams Phone” as the whole answer. It’s the calling system — the PBX layer — and on its own it only covers internal and feature calling. External calling needs a second layer: a Microsoft Calling Plan, Operator Connect, or Direct Routing. Pick that PSTN route first, because it decides what you actually buy.
For services, remember the resource account license is free but conditional: it only appears once your tenant owns a paid Teams Phone license, and it has to be assigned before a number will stick. Get the layers and the order right and the calling features fall into place. From here, decide your PSTN model with Calling Plan vs Operator Connect vs Direct Routing, then browse more in the Microsoft Teams guides.
