Using 3CX with Microsoft Teams
How 3CX works alongside Microsoft Teams so staff can make and receive external calls right from the Teams app.
Plenty of Melbourne businesses live in Microsoft Teams all day. Staff chat, share files and run video meetings there, so it makes sense to ask the obvious question: can we make and take normal phone calls in Teams too? The answer is yes, and 3CX is one of the cleaner ways to do it without paying Microsoft's per-user calling premium.
This guide explains how 3CX and Teams work side by side, the two practical paths to phone calls in Teams, and what to weigh up before you commit. We will keep it conceptual rather than click-by-click, because menus change between builds but the ideas below hold.
Two systems, two jobs
Teams is excellent at internal collaboration: messaging, presence, meetings and screen sharing. What it does not do out of the box is connect you to the outside phone network. To dial a mobile, ring a supplier or answer a customer on your 1300 number, you need a telephony layer underneath.
That is where 3CX comes in. It is a full business phone system: Extensions, Inbound Rules for DID routing, Outbound Rules, a Digital Receptionist, Ring Groups, Call Queues, voicemail-to-email and call recording. It connects to the public phone network through a SIP trunk. Think of Teams as the collaboration hub and 3CX as the engine that handles real phone calls.
The two ways to combine them
There are two genuinely different approaches, and it pays to understand which one you are buying.
Run 3CX alongside Teams.
Your team keeps using Teams for chat and meetings, and uses the 3CX Web Client, desktop app or mobile app for phone calls. The 3CX app sits next to Teams on the same screen. This is the simplest, lowest-cost path and works on day one.
Direct Routing into Teams.
Here you keep dialling and answering inside the Teams app itself, using the Teams dial pad. 3CX (or your SIP trunk) provides the actual phone line behind the scenes via Microsoft Teams Direct Routing. Staff never leave Teams to make an external call.
Businesses that simply want phones working quickly start with option one. Those that want Teams to be the single app on every desk move to Direct Routing. Neither is wrong.
Option one: 3CX running next to Teams
This is the path of least resistance. You install 3CX, connect a SIP trunk, set up your Extensions and routing, and your people make calls from the 3CX apps while keeping Teams open for everything else. What you get:
External calls straight away
through the 3CX Web Client, the desktop app for Windows or Mac, or the mobile app for iOS and Android.
Full PBX features
such as Call Queues with polling strategies (Hunt/Ring all, Round robin, Least talk time, Longest waiting), Digital Receptionist menus, Office Hours routing and call recording.
No extra Microsoft calling licence
, because the calling happens in 3CX rather than inside Teams.
The trade-off is that staff use two apps. For many offices that is a non-issue, and 3CX can integrate with Microsoft 365 so user accounts and contacts line up between the two.
Option two: Direct Routing, calls inside Teams
If the goal is one app for everyone, Direct Routing connects 3CX (or a SIP trunk) to Teams as its phone carrier. Your staff click the dial pad in Teams, the call leaves through your trunk, and the rest of the world sees your business number.
This is the tidier experience for end users, but be honest about the moving parts:
- It needs the right Microsoft licensing. Teams Phone (Phone System) entitlements are required for users who place external calls via Direct Routing, so check what your Microsoft 365 plan already includes.
- It involves Session Border Controller configuration, certificates and DNS records on the Teams side, which is fiddlier than a standard SIP trunk.
- Some advanced 3CX call-handling features behave differently once calls live inside Teams, so plan how queues, IVR and after-hours routing will work.
This is the part we recommend leaving to someone who has done it before. The concepts are simple; the certificate and routing setup is where projects stall. SIP Connect sets up both approaches for Melbourne businesses and can tell you, after a look at your Microsoft 365 setup, which one costs less and causes fewer headaches. Call us on 1300 747 266 or grab a free bill review.
What you need in place
Whichever route you take, a few things underpin a clean result:
- A SIP trunk for connection to the phone network. Our connecting a SIP trunk to 3CX guide walks through it, and SIP trunks explained covers the basics.
- Your numbers ported across cleanly so customers keep ringing the same line. See number porting.
- Enough internet headroom, because voice and Teams traffic share the same pipe. A solid business NBN service, and often internet failover, keeps calls steady.
- Sensible security limits on the 3CX side. Outbound rules and anti-fraud caps stop a compromised extension running up a bill overnight.
If you are still weighing the platforms themselves, our 3CX vs Microsoft Teams comparison is a good companion read.
What we see installing this in Melbourne
Most of the Melbourne SMEs we talk to land on option one first. They already pay for Microsoft 365 Business Standard, which does not include Teams Phone, and the cost of adding the calling licence per seat usually outweighs running the 3CX app next to Teams. Once we explain that, the decision becomes easy.
Where Direct Routing projects stall on AU sites is almost always the same trio: a Microsoft 365 plan that turns out to need a Teams Phone add-on, an SBC certificate chain that does not match the public DNS, and an office NBN connection with thin upload. We test calls on the actual office link before quoting, because a fibre-to-the-node service in an older Melbourne suburb behaves very differently to FTTP in a newer estate.
The other thing worth flagging early is call recording. If you record customer calls, both parties need to be informed under Australian law, and Direct Routing changes where the recording happens. We sort that during the cutover so nobody finds out the hard way.
Frequently asked questions
Can I make external phone calls in Microsoft Teams without 3CX?
You can, but you would need Microsoft's own calling plans or a separate Direct Routing carrier, and the per-user cost adds up. Pairing Teams with 3CX gives you a full phone system, including queues, IVR and recording, usually for less than Microsoft's calling licences.
Do my staff have to learn a new app?
It depends on the path. With 3CX running alongside Teams, they keep Teams open and use the 3CX app for calls, which most people pick up in minutes. With Direct Routing, calls happen inside the Teams dial pad they already know, so there is even less to learn.
Will Direct Routing work with my current Microsoft 365 plan?
Sometimes. External calling through Direct Routing needs Teams Phone (Phone System) entitlements, which not every plan includes. We can check your licensing before you spend anything and tell you whether running 3CX alongside Teams is the smarter first step.
Is this hard to set up ourselves?
Running 3CX next to Teams is straightforward. Direct Routing is more involved because of the certificate, DNS and Session Border Controller work, and it is the part most businesses hand to a local specialist. We are in Greensborough and do this regularly.
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