The practical answer
A Teams Phone licence enables cloud PBX capabilities. It does not, by itself, provide every user with public telephone network connectivity, a phone number, and unlimited calling. A complete design separates four things: the user’s Microsoft Teams entitlement, the Teams Phone entitlement, the PSTN connectivity option, and any usage, number, resource-account, or add-on requirements. Most purchasing mistakes happen when those layers are collapsed into one SKU.
The licensing stack
The user needs an eligible Teams entitlement. Depending on market and the suite purchased, Teams may be included or sold separately.
Option 1: Microsoft Calling Plans
Microsoft is the PSTN provider and supplies numbers and calling service in supported markets. This can be operationally simple because administration, number assignment, and the cloud phone platform sit closely together.
Option 2: Operator Connect
Operator Connect uses a participating carrier integrated with the Teams admin experience. The operator supplies PSTN service and manages the underlying connectivity while the customer can provision numbers through the supported workflow.
The licensing stack
Microsoft Teams access The user needs an eligible Teams entitlement. Depending on market and the suite purchased, Teams may be included or sold separately. Do not assume that two organisations buying a similarly named Microsoft 365 suite receive the same Teams inclusion.
- Teams Phone Teams Phone provides calling features such as call control, voicemail, transfer, delegation, and cloud PBX functionality. Some suites include it; others need a Teams Phone add-on.
- PSTN connectivity
- External calls require one of Microsoft’s supported PSTN models: Microsoft Calling Plans, Operator Connect, Direct Routing, or another supported scenario such as Teams Phone Mobile. The choice determines the carrier relationship, geographic availability, number management, usage charges, and operating model. Shared calling features
- Auto attendants and call queues use resource accounts and specific licensing rules. Calling on behalf of a resource account can also create funding or carrier requirements. Validate inbound and outbound scenarios, not just whether the menu can be configured.
Option 1: Microsoft Calling Plans
Microsoft is the PSTN provider and supplies numbers and calling service in supported markets. This can be operationally simple because administration, number assignment, and the cloud phone platform sit closely together. It is a strong fit where Microsoft coverage meets the organisation’s countries, number types, emergency-calling needs, and usage profile. Verify availability per location; a global tenant does not imply global Calling Plan coverage. The commercial design may include bundled minute plans or pay-as-you-go, depending on market and offer. Model domestic, international, toll-free, and premium usage separately. Include Communications Credits or another funded mechanism where the documented scenario requires it.
Option 2: Operator Connect
Operator Connect uses a participating carrier integrated with the Teams admin experience. The operator supplies PSTN
- service and manages the underlying connectivity while the customer can provision numbers through the supported workflow.
- It is often a good middle ground for organisations that want to retain or choose a carrier without managing a certified
- session border controller. Compare operator coverage, contract terms, porting capability, support ownership, emergency calling, resilience, and lead times country by country.
- The Microsoft licence and the operator’s charges are separate parts of the total cost.
Option 3: Direct Routing
Direct Routing connects Teams Phone to a supported session border controller and a chosen telephony carrier or existing voice infrastructure. It offers the greatest control and can support complex carrier, PBX coexistence, contact-centre, analogue-device, or geographic requirements. That flexibility adds engineering and operational responsibility. The design needs a supported SBC, certificates, DNS, routing, high availability, monitoring, security, emergency calling, number management, and clear support boundaries. Carrier savings can be outweighed by unmanaged complexity. Direct Routing is not simply the “cheap” option; it is the controlled-integration option.
How to choose
Use the following decision order: Geography: Which countries, number types, and emergency-calling obligations are in scope?
- Carrier strategy: Must the organisation retain contracts or numbers with an existing operator?
- Integration: Are legacy PBXs, analogue devices, contact centres, recording, or specialist routing required?
- Control: Does the internal team want responsibility for an SBC and voice routing? Resilience: What happens if the carrier, internet path, Microsoft service, or SBC fails?
- Support: Who owns number porting, fraud, call quality, routing, and incident coordination?
Practical checks
Cost: Compare Microsoft licences, operator charges, usage, SBC/infrastructure, support, and implementation—not only the seat price.
Auto attendants, call queues, and resource accounts
Microsoft documents prerequisites for auto attendants and call queues, including at least one Teams Phone licence in the organisation and free resource-account licences
- assigned to resource accounts. The resource account also needs a supported telephone-number and PSTN configuration when it receives or makes external calls.
- Microsoft’s current guidance notes that from 1 November 2025, outbound calls made on behalf of resource accounts using Microsoft Calling Plan
- service numbers require a funded pay-as-you-go mechanism or Communications Credits. Operator
- Connect and Direct Routing follow their applicable carrier configuration instead.
Practical checks
Test transfers, callbacks, outbound caller ID, overflow, after-hours routing, and emergency behaviour. An inbound-only test does not validate the complete call flow.
Common mistakes
Buying Teams Phone and assuming PSTN service is included. Forgetting that Teams itself may be a separate entitlement.
- Selecting a model before checking country and number availability.
- Ignoring number-porting lead times and losing the old carrier too early.
- Using resource accounts without the correct licences or funding path. Comparing Calling Plans with carrier rates while excluding SBC and support costs.
- Running Direct Routing without monitored redundancy.
Practical checks
Treating emergency calling as a final configuration task.
Deployment checklist
User personas and required calling features Countries, offices, remote users, and emergency locations
- Teams and Teams Phone entitlement per user PSTN option and carrier contract per location
- Number inventory and porting sequence
- Resource accounts, auto attendants, and call queues Usage funding, toll-free, and international controls
- Recording, compliance, contact-centre, and device requirements Resilience, monitoring, support, and rollback
Practical checks
The right model is the one that fits the organisation’s geography and operating capability, not the one with the shortest SKU list. For a licence and telephony architecture review, contact Axeti .
Sources and scope: This article follows Microsoft’s Teams add-on licensing guidance , Operator Connect plan , Direct Routing plan , and auto attendant and call queue prerequisites . Availability and licensing vary by country and agreement; verify the current tenant, offer, carrier, and emergency-calling requirements before deployment.
