Microsoft Teams PSTN calling setup – Enable PSTN calling in Microsoft Teams with this complete setup guide. Learn how to configure Teams Phone, Caller ID, and emergency calling for your business.
Microsoft Teams has evolved far beyond a simple chat or meeting app – it’s now a complete communication and collaboration platform. One of its most powerful (yet often overlooked) features is PSTN calling – the ability to make and receive regular phone calls directly inside Teams.
If you’ve ever wanted your employees to answer and make external calls from Teams – using their laptops, mobile devices, or Teams-certified phones – this guide will show you exactly how to set it up.
What Is PSTN Calling in Microsoft Teams?
PSTN (Public Switched Telephone Network) is the traditional phone network – the same system that routes calls between landlines and mobile phones.
When you integrate PSTN with Teams, your users can dial standard phone numbers (not just Teams users) and receive incoming calls from the outside world. In simple terms, it turns Teams into a full business phone system.
You can think of it as connecting your cloud-based collaboration tool to the “old-school” phone network — without needing physical desk phones or a traditional PBX.
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Why PSTN Calling Matters
While most internal communication happens through chat and video calls, external communication often still relies on phone calls. PSTN integration allows you to:
- Reach external clients or partners who use regular phone lines.
- Replace outdated PBX systems and consolidate voice and collaboration in one platform.
- Support remote workers who need access to business phone numbers from anywhere.
- Reduce telephony costs by moving to a modern, cloud-based calling solution.
In short, PSTN calling makes Teams your single hub for every form of communication – chat, meetings, and voice calls.
The Three Main PSTN Options in Microsoft Teams
Before diving into setup, you need to decide how Teams will connect to the phone network. Microsoft provides three main options:
1. Microsoft Calling Plan
This is the simplest option. Microsoft acts as your phone carrier.
You purchase calling plans directly from Microsoft – either Domestic or International – and manage everything in the Teams admin center.
Ideal for small and mid-sized businesses that want an easy, all-in-one setup with minimal technical complexity.
2. Operator Connect
Operator Connect allows you to use your existing telecom provider (if they’re a Microsoft-certified operator).
You keep your current phone service, but the connection to Teams is handled via Microsoft’s cloud.
It’s a great balance between simplicity and flexibility – no need to manage complex networking, but you still use your preferred carrier and keep your existing numbers.
3. Direct Routing
Direct Routing gives you maximum control and customization.
It connects your on-premises Session Border Controller (SBC) to Microsoft Teams. You can integrate with your existing PBX or SIP trunk, choose any carrier, and route calls based on business logic.
Best suited for large enterprises or organizations with existing telephony infrastructure that they want to retain or customize deeply.
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Step-by-Step: How to Set Up PSTN Calling in Microsoft Teams
Once you’ve chosen your preferred PSTN method, here’s how to configure Teams for external calling.
Step 1: Purchase and Assign Licenses
- Log in to the Microsoft 365 admin center.
- Go to Billing > Purchase services and get the Teams Phone add-on license (included in Microsoft 365 E5, or as an add-on for E3 and Business plans).
- If you’re using a Calling Plan, purchase the Microsoft Calling Plan license as well.
- Assign the licenses to each user who needs to make or receive PSTN calls:
- Navigate to Users > Active users, select the user, and add the Teams Phone and Calling Plan licenses.
Once assigned, these users will have access to the dial pad inside Teams.
Step 2: Choose Your PSTN Connectivity Option
Based on your organization’s needs, set up one of the following:
- Calling Plan: Microsoft manages all your numbers and routing automatically.
- Operator Connect: Link your chosen operator through the Teams admin center under Voice > Operators and follow the on-screen prompts.
- Direct Routing: Configure your SBC to connect with Microsoft’s cloud. You’ll need a public certificate and SIP trunk configured to route calls into Teams.
Each option requires administrative permissions in Teams and some network planning to ensure call quality.
Step 3: Acquire and Assign Phone Numbers
You’ll now need to give users real phone numbers.
- In the Teams admin center, go to Voice > Phone numbers.
- Choose Add to get new numbers. You can order them directly from Microsoft or import existing numbers from your current provider (porting).
- Specify:
- Country or region
- Type (User, Service, or Toll-Free)
- Quantity of numbers required
- After the numbers appear in your list, go to Users > Manage users, select a user, and assign a number to their account.
Once assigned, the number will automatically appear in their Teams client as their outbound caller ID.
Step 4: Set Up Emergency Calling
This is one of the most important compliance steps.
- In the Teams admin center, navigate to Voice > Emergency addresses.
- Add your company’s official emergency address (for example, your office location).
- If users work from multiple sites, create separate emergency locations for each.
- Assign the correct address to each user’s phone number.
This ensures that emergency services can identify the user’s location if someone dials an emergency number (like 911 or 112) from Teams.
Step 5: Configure Advanced Features (Optional but Recommended)
Once calling is active, you can enhance the experience with advanced features:
Auto Attendants
Set up automated menus that greet callers and direct them to the right department (“Press 1 for Sales, Press 2 for Support”).
Call Queues
Create call queues to distribute incoming calls to available team members – ideal for helpdesks or support lines.
Voicemail and Call Forwarding
Users can configure voicemail greetings, call forwarding, and simultaneous ring directly in their Teams settings.
Step 6: Configure Caller ID to Show Your Company Name
By default, Teams shows a user’s assigned phone number when they make an external call. You can change this to display your company name instead:
- Open the Teams Admin Center and go to Voice > Caller ID policies.
- Create a new policy or edit an existing one.
- Under “Calling Party Name (CNAM)”, enter your company’s display name – for example, “Contoso Ltd”.
- Assign the policy to all users who should display this Caller ID.
After this, external recipients will see your company name when your users call, instead of individual phone numbers. (Note: Some carriers may control how the name is displayed.)
Step 7: Test and Train Users
Before rolling out to the entire organization:
- Test inbound and outbound calls from multiple users.
- Confirm Caller ID, voicemail, and emergency calling work correctly.
- Educate users on how to make calls, check voicemail, transfer, and join PSTN audio conferences.
Providing concise user guides or brief training sessions can significantly enhance adoption and decrease helpdesk tickets.
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Tips and Best Practices
Start with a pilot: Roll out to a small group first to validate network quality and configurations.
Check your network readiness: Use Microsoft’s network assessment tool to confirm sufficient bandwidth and QoS settings.
Use Teams-certified devices: Headsets, speakerphones, and handsets certified for Teams deliver the best audio quality.
Monitor usage and call quality: Regularly review Teams admin reports to ensure consistent performance.
Compliance plan: If your industry requires call recording or retention, integrate a certified third-party solution.
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Final Thoughts
Setting up PSTN calling in Microsoft Teams turns it into a complete cloud-based phone system, replacing traditional desk phones and PBX infrastructure.
Whether you choose Microsoft Calling Plans, Operator Connect, or Direct Routing, Teams Phone gives your organization a flexible, scalable, and future-proof communication system.
With a single platform for chat, meetings, and external phone calls, Teams helps businesses simplify their communication stack, empower hybrid work, and stay connected anytime, anywhere.
To wrap up, mastering your Microsoft Teams PSTN calling setup is the key to unlocking a truly unified communication experience. Whether you’re working through a Teams Phone System configuration, setting up a Microsoft Calling Plan, or exploring a Teams Direct Routing guide for more advanced control, the goal remains the same — seamless connectivity. Many organizations also benefit from a Teams Operator Connect setup, which blends simplicity with flexibility. Don’t forget to fine-tune your Caller ID configuration in Teams and ensure proper Teams emergency calling setup for compliance and safety. With the right planning and PSTN integration for Microsoft Teams, your business can connect, collaborate, and communicate without limits.