How to Integrate 3CX with Microsoft Teams: Complete Guide 2026

Microsoft Teams is where your team works — chat, meetings, files, projects. But making and receiving actual phone calls through Teams? That’s where most businesses hit a wall.

By default, Teams doesn’t connect to the phone network. You need either Microsoft Calling Plans (expensive, limited) or a third-party phone system with direct routing. 3CX is one of the best options for this — it lets you make and receive calls through Teams using your existing SIP trunks at a fraction of the cost of Microsoft’s calling plans.

In this guide, we’ll cover exactly how 3CX integrates with Microsoft Teams, what you need, how to set it up, and the real-world benefits and limitations.

What Is 3CX + Teams Integration?

3CX integrates with Microsoft Teams via direct routing. This means 3CX acts as the connection between Teams and the public phone network (PSTN) through SIP trunks.

The result: your team can make and receive phone calls — to landlines, mobiles, international numbers — directly from the Teams interface. Calls are handled by your 3CX phone system, routed through your SIP trunks, but the user experience is entirely within Teams.

What your users see:

• The Teams dial pad works for external calls
• Incoming calls ring in Teams (desktop and mobile)
• Call history shows in Teams
• They can transfer, hold, and manage calls from Teams
• Contacts sync between 3CX and Teams

What happens behind the scenes:

• 3CX connects to your SIP trunk provider for PSTN connectivity
• Direct routing bridges 3CX to the Teams backend via Microsoft’s SBC (Session Border Controller) integration
• Call routing, IVR, queues, and recording are handled by 3CX
• Teams is the front-end interface your users interact with

Why Use 3CX Instead of Microsoft Calling Plans?

Microsoft offers its own calling plans for Teams, but there are significant reasons why businesses choose 3CX instead:

Cost

Microsoft Calling Plans cost £6-10/user/month for domestic calling, plus £3-9/user/month for the required Phone System licence. For 50 users, that’s £450-950/month — just for basic calling.

3CX licensing for 50 users is roughly €295/year for the whole system. Add SIP trunk costs (typically €5-10/user/month) and you’re still paying a fraction of Microsoft’s pricing.

Flexibility

With Microsoft Calling Plans, you’re locked into Microsoft’s call rates, coverage, and features. With 3CX + direct routing:

• Choose any SIP trunk provider (compare rates, switch providers)
• Keep your existing phone numbers
• Use 3CX’s advanced features (call queues, IVR, wallboards, recording)
• Host the phone system wherever you want

Features

3CX includes call centre features that Microsoft doesn’t offer natively in Teams:

• Call queues with wallboards and live stats
• Agent performance reporting
• Call recording on all plans
• Multi-level IVR / auto-attendant
• Advanced call routing by time, caller ID, availability

With Microsoft’s native solution, you’d need to buy additional products (Teams Phone, Queues, Auto Attendant licences) to get similar functionality.

What You Need

Prerequisites

1. Microsoft 365 licences with Teams (Business Basic, E1, E3, or E5)
2. Microsoft Teams Phone licence (included in E5, add-on for other plans — ~£6/user/month)
3. 3CX Pro or Enterprise licence (supports Teams integration)
4. SIP trunks from a provider like ITelecoms
5. A verified domain in Microsoft 365
6. An SBC (Session Border Controller) — 3CX includes this capability, or you can use a dedicated SBC

Network Requirements

• Stable internet connection with sufficient bandwidth (100kbps per concurrent call)
• Ports opened for SIP signalling and RTP media
• QoS (Quality of Service) configured on your network for voice traffic prioritisation

How to Set Up 3CX + Teams Integration

Step 1: Configure Your 3CX System

• Install or access your 3CX system (cloud or on-premise)
• Ensure you’re on a Pro or Enterprise licence
• Configure your SIP trunks and verify inbound/outbound calling works

Step 2: Enable Microsoft 365 Integration in 3CX

• In the 3CX Management Console, go to Settings → Microsoft 365 Integration
• Sign in with your Microsoft 365 admin account
• Authorise 3CX to connect to your Microsoft 365 tenant
• 3CX will sync your Teams users automatically

Step 3: Configure Direct Routing in Microsoft 365

• In the Microsoft Teams Admin Centre, go to Voice → Direct Routing
• Add your 3CX SBC as a gateway (3CX provides the FQDN and port)
• Create voice routing policies to define which calls go through 3CX
• Assign the policies to your users

Step 4: Assign Phone Numbers

• In 3CX, assign DID numbers (from your SIP trunk) to users
• Map these numbers to the corresponding Teams users
• Configure call routing rules (what happens when a Teams user is offline, busy, etc.)

Step 5: Test

• Make an outbound call from Teams to a mobile/landline — verify it routes through 3CX and your SIP trunk
• Have someone call your number — verify it rings in Teams
• Test call transfer, hold, voicemail, and call recording
• Check the 3CX call logs to confirm calls are being tracked

What Works and What Doesn’t

Works Well

• Making and receiving calls in Teams desktop and mobile
• Dial pad in Teams for outbound calls
• Incoming call notifications in Teams
• Call transfer and hold from Teams
• Presence sync — Teams shows when users are on a call
• Voicemail — handled by 3CX, notifications in Teams

Limitations

• Call queues and IVR are managed in 3CX, not in Teams — agents need 3CX for queue visibility
• Wallboards and reporting use the 3CX interface, not Teams
• Some advanced call features (e.g. barge, whisper, listen) require the 3CX client
• Teams admin knowledge required — direct routing setup needs someone familiar with Microsoft 365 admin

3CX + Teams vs RingCentral for Teams

Frequently Asked Questions

Do all my users need a Microsoft Teams Phone licence?

Only users who need to make/receive external (PSTN) calls need the Phone licence. Internal Teams-to-Teams calling works without it.

Can I keep my existing phone numbers?

Yes. You port your numbers to your SIP trunk provider, then route them through 3CX to Teams. Your numbers don’t change.

Does call recording work through Teams?

Yes. 3CX records calls on the server side regardless of whether the call was made through Teams, the 3CX app, or a desk phone.

What if a user isn’t on Teams — can they still use 3CX?

Yes. 3CX has its own desktop, web, and mobile apps. Users can mix and match — some on Teams, some on the 3CX client, some on desk phones. They all connect to the same 3CX system.

Can ITelecoms set this up for me?

Yes. We handle the full setup — 3CX configuration, Microsoft 365 direct routing, SIP trunks, number porting, testing, and training. Contact us to get started.

Want 3CX integrated with your Microsoft Teams? ITelecoms handles the full setup — from SIP trunking to direct routing configuration. Get in touch today.