Microsoft Teams Phone System Integration: How to Make It Work Properly with 8x8, 3CX, Gamma and Zoom

Most UK businesses already live in Microsoft Teams.

It's where staff chat, meet, share files and pretend they know where things are saved.

So the next question almost always comes up:

Can we run our phone system through Teams as well?

The answer is yes.

But that doesn't mean Teams should automatically become your entire phone system.

For some businesses, Teams Phone is enough.

For others, Teams works best when it's connected to a proper cloud phone system from providers like 8x8, 3CX, Gamma or Zoom Phone.

That's where it gets interesting.

Because the real win isn't just making calls from Teams.

It's making Teams part of a setup that handles customers properly, routes calls cleanly, records what needs recording, and connects with the tools your business already uses.

Why Teams Is Suddenly Part of the Phone System Conversation

Microsoft Teams used to be an internal tool.

Chat with colleagues. Join the odd meeting. Share a file.

Now it's the main workspace for millions of people.

That creates a natural question. If staff are sitting in Teams all day, why make them jump into another app to answer a customer call?

This is why Teams phone system integration has become a big topic in 2026.

Done well, it can:

Cut down the number of apps staff use
Make hybrid and remote calling easier
Bring voice into the same place as chat and meetings
Replace ageing on-premise phone systems
Improve call routing and customer handling
Connect calls with CRM and business systems

But there's a catch.

A phone system isn't just a dial pad.

It's call queues, reception routing, call recording, reporting, numbers, failover, mobiles, desk phones, contact centre features and proper support.

That's why the right setup matters.

Can Microsoft Teams Replace Your Phone System?

Sometimes, yes.

Microsoft Teams Phone gives users the ability to make and receive external calls through Teams. For a small business with simple needs, that may be all you need.

But many organisations need more than basic calling.

Think about a school reception team, a financial services firm, a law office, a sales floor or a business with multiple sites. They aren't just making the odd call.

They're managing call flows, busy periods, missed calls, recordings, reporting and customer records.

That's where Teams on its own starts to feel limited.

In those cases, Teams works better as the front end, with a stronger phone system working behind it.

That could be 8x8, 3CX, Gamma, Zoom Phone or another platform we partner with.

So the better question isn't:

"Can Teams be our phone system?"

It's:

"What do we actually need our phone system to do?"

The Four Ways Microsoft Teams Connects to External Calling

Microsoft offers four official PSTN connectivity options for Teams Phone. The right one depends on your existing setup, where your users sit and how complex your call flows are.

1. Microsoft Calling Plans

Microsoft is the carrier.

You buy a Calling Plan licence per user, get numbers from Microsoft and manage everything in the Teams Admin Center.

Good for simple setups. Limited in coverage (around 30–35 countries) and on flexibility.

2. Operator Connect

A Microsoft-certified telecoms operator provides the calling service and connects it directly into Teams.

You keep your preferred carrier and contracts. The operator manages the SBCs and PSTN side. You assign numbers in the Teams Admin Center.

Faster to deploy than Direct Routing. Often cheaper than Calling Plans at scale.

8x8 and Gamma are both Operator Connect partners.

3. Direct Routing

Connects Teams to any carrier or phone system via a Session Border Controller (SBC).

Most flexible. Best for businesses that need to keep an existing carrier, integrate with a legacy PBX, or run complex call routing across sites.

This is the route most often used for 3CX and Zoom Phone integration.

4. Teams Phone Mobile

A user's mobile SIM number becomes their Teams phone number. The same number rings on the native dialler and the Teams app.

Useful for field-based, mobile-first staff. Adoption is still small — around 5% of Teams Phone users — but growing.

Where 8x8 Fits with Microsoft Teams

8x8 is a strong option for businesses that want Teams integration but also want a serious communications platform behind it.

With 8x8 for Microsoft Teams, users get the familiar Teams interface while 8x8 handles the voice, contact centre, analytics, call recording and global calling.

It's useful where Teams alone doesn't go far enough.

8x8 is often the right fit if you need:

A proper cloud phone system, not just a dial pad
Contact centre capability with skills-based routing
Call recording and compliance
Real reporting and analytics
AI-powered customer experience tools (8x8 AI Studio)
A single platform for voice, video, messaging and contact centre
Multi-site or international support

In plain English:

Teams keeps the users happy. 8x8 gives the business the phone system power behind it.

Where 3CX Fits with Microsoft Teams

3CX integrates with Microsoft Teams using Direct Routing.

It's a strong fit when you want Teams users and 3CX users to coexist, rather than moving everyone to one platform overnight.

3CX is often the right answer if you need:

A cost-effective phone system
Strong call routing, IVRs and queues
Call recording and reporting
Reception and department-level control
A practical migration path from an older PBX

For some businesses, 3CX stays as the main phone system and Teams is added for selected users.

For others, Teams becomes the daily calling interface and 3CX handles the telephony logic behind the scenes.

It's a flexible "best of both" setup.

Where Gamma Fits with Microsoft Teams

Gamma is one of the UK's biggest voice providers and offers Microsoft Teams calling through both Operator Connect and Direct Routing.

It's a good fit for UK businesses that want:

Proper UK voice services
Number porting handled by a UK provider
Business-grade calling and SLAs
A telecoms partner managing the voice side
Channel-supported deployment (which is where we come in)

For businesses already on Gamma SIP, integrating Teams is often the cleanest way to modernise calling without ripping anything out.

It's also a good shout if you want UK-based voice expertise behind your Teams setup, rather than configuring it all yourself.

Where Zoom Phone Fits with Microsoft Teams

Some businesses use Teams for internal collaboration but prefer Zoom for calling and meetings.

That's more common than people think.

Zoom Phone integrates with Microsoft Teams so users can stay in the Teams environment while Zoom handles the voice platform.

It suits businesses that:

Already use Zoom Phone or Zoom Meetings
Prefer Zoom's voice and video experience
Want Teams compatibility without moving all calling to Microsoft
Run a mixed Microsoft and Zoom environment

Not every business lives entirely inside one ecosystem.

A good phone system should work around the business, not force everyone into one rigid setup.

Microsoft Teams + CRM and Business Software

This is where proper integration earns its keep.

Once Teams is connected to a real phone system, calls become part of the wider customer journey.

A customer rings in.

The system recognises their number.

The right record opens on screen.

The call gets routed to the right person.

The conversation is logged automatically.

Managers can report on call volumes, missed calls and response times.

That's the difference between "we made a call in Teams" and "we ran our business through Teams."

Common integrations include:

CRM systems (Salesforce, HubSpot, Dynamics)
Helpdesk platforms
ERP systems
MIS platforms for schools
Customer service tools
Call recording platforms

Microsoft Teams + Contact Centre

Teams can handle basic call queues and auto attendants.

But if you're running a customer service team, sales operation, support desk or any high-volume call environment, you'll outgrow it quickly.

That's where contact centre platforms from 8x8 and Zoom come in.

A proper contact centre setup gives you:

Skills-based routing
Queue management and callbacks
Supervisor dashboards and wallboards
Real reporting and customer experience analytics
AI summaries and agent performance tracking
Omnichannel support — voice, chat, email, social

For a small team, Teams call queues are fine.

For a customer service operation, school reception, housing team or financial services firm, a dedicated contact centre platform is the better answer.

Is Teams Phone Actually Good Enough?

Honest answer: it depends on how you handle calls.

Ask yourself:

Do you need basic calling, or proper call management?
Do you need call recording for compliance?
Do you need CRM integration?
Do you need contact centre features?
Do you need detailed reporting?
Do you need different routing by department or site?
Do you need to keep existing SIP services?
Do you want desk phones, softphones and mobiles all working together?

If most answers are no, Teams Phone alone is probably enough.

If most answers are yes, Teams should be integrated with something stronger.

The Risks of Getting Teams Integration Wrong

Teams phone integration isn't a licence change.

It's a phone system project.

We've seen plenty of businesses bodge it together and regret it. Common issues:

Poor call routing when reception teams need it most
Numbers lost or stuck during porting
Users licensed incorrectly (and getting billed for it)
Call queues set up badly
No failover when something breaks
Patchy reporting
No clear ownership between Microsoft, the carrier and the phone provider
Call recording gaps that cause compliance issues
Reception teams losing features they relied on

The biggest mistake is treating Teams Phone as a simple swap.

It isn't. The technology needs to match how the business actually handles calls.

A Quick Checklist Before You Move Calls Into Teams

Before changing anything, run through this:

How many users actually need external calling?
Which users only need internal Teams calling?
Do you need to keep existing numbers?
Are any numbers linked to lifts, alarms, payment terminals or door entry?
Do you need call recording?
Do you need contact centre features?
Do you need CRM integration?
Do reception teams need physical desk phones?
Do users need mobile integration?
Do you need out-of-hours routing?
Multiple sites? International numbers?
Do you already use 8x8, 3CX, Gamma or Zoom?
Do you want Teams to be the phone system, or just the calling interface?

Get these right at the start and you save yourself a lot of pain later.

Which Phone System Should You Pick?

Quick rules of thumb:

Choose Teams Phone if your requirements are simple, Microsoft-native and you don't need much beyond calling.

Choose 8x8 if you want proper UCaaS, contact centre features, analytics and AI alongside Teams.

Choose 3CX if you want a flexible, cost-effective phone system with Teams coexistence.

Choose Gamma if you want UK voice expertise and a telecoms provider managing the voice side.

Choose Zoom Phone if you already use Zoom and want Teams compatibility.

A good provider should explain these options clearly, not just push the one they earn the most on.

How West Pier Helps

West Pier Technologies helps UK businesses connect Microsoft Teams with the right phone system, voice provider and communications platform.

We work with 8x8, 3CX, Gamma, Zoom and Microsoft Teams Phone — alongside other UCaaS and contact centre solutions.

Our job is to work out the right setup, not just sell you a licence.

That means:

Reviewing your current phone system
Checking your Microsoft 365 and Teams setup
Mapping your actual call flows
Reviewing numbers and porting requirements
Recommending the right Teams voice option
Integrating with CRM, email, ERP or MIS where needed
Supporting deployment, training and ongoing management

Some businesses need Teams Phone.

Some need 8x8 with Teams.

Some need 3CX with Teams.

Some need Gamma Operator Connect.

Some need Zoom Phone.

Some need a proper contact centre.

The point is to build the setup around how your business actually works.

Final Thoughts: Teams Isn't Always the Phone System, But It Can Be the Front Door

Microsoft Teams has changed how businesses communicate.

But when it comes to calling, the best answer isn't always to put everything inside Microsoft and hope for the best.

For many businesses, Teams works best as the place users make and receive calls, while a specialist phone system or telecoms provider handles the voice service behind it.

That gives staff a familiar experience.

It gives the business more control.

And it gives customers a better chance of getting through to the right person, first time.

If you already use Teams and you're reviewing your phone system, now's a good time to look at how it all connects.

FAQ

Can Microsoft Teams integrate with a phone system?

Yes. Teams integrates with phone systems through Operator Connect, Direct Routing and platforms including 8x8, 3CX, Gamma and Zoom Phone.

Can I use Microsoft Teams as my business phone system?

Yes, Teams Phone can act as a business phone system. But for advanced call routing, recording, reporting, CRM integration or contact centre needs, most businesses pair Teams with a specialist provider.

What is Operator Connect for Microsoft Teams?

Operator Connect lets a Microsoft-certified telecoms operator provide PSTN calling directly inside Teams. You manage everything in the Teams Admin Center and the operator handles the voice infrastructure.

What is Direct Routing for Microsoft Teams?

Direct Routing connects Teams Phone to any carrier or PBX through a Session Border Controller (SBC). It's the most flexible PSTN option and the route most often used for 3CX and Zoom Phone integration.

Does 8x8 integrate with Microsoft Teams?

Yes. 8x8 offers Microsoft Teams integration through Operator Connect and a Teams-connected voice and contact centre service.

Does 3CX integrate with Microsoft Teams?

Yes, via Direct Routing. It's particularly useful for businesses running both 3CX and Teams during a migration, or those who want Teams as the user interface and 3CX as the phone system.

Does Gamma work with Microsoft Teams?

Yes. Gamma provides Microsoft Teams voice services through both Operator Connect and Direct Routing — a popular choice for UK businesses.

Does Zoom Phone integrate with Microsoft Teams?

Yes. Zoom Phone can integrate with Teams, which suits businesses running both Microsoft 365 and Zoom day-to-day.

Do I need a Microsoft Teams Phone licence?

In almost all cases, yes. Users need the correct Teams Phone licensing to make and receive external calls. The exact licence depends on your Microsoft 365 plan and chosen voice route.

Is Teams Phone better than 3CX, 8x8 or Zoom Phone?

It depends on what you need. Teams Phone is fine for simple calling. 8x8, 3CX, Gamma and Zoom Phone are usually better when you need stronger call routing, contact centre features, reporting, recording or telecoms-grade support.

Can Microsoft Teams integrate with a CRM?

Yes — through Teams Phone or via integrated platforms like 8x8, calls can be logged, matched to records, routed by customer data and connected with helpdesk, ERP and email tools.

What's the best Microsoft Teams phone system for UK businesses?

It depends on the business. Small organisations may only need Teams Phone. Businesses with more complex needs are usually better suited to 8x8, 3CX, Gamma or Zoom Phone alongside Teams.

Speak to a UK Microsoft Teams & Phone System Specialist

West Pier Technologies designs and supports cloud phone systems, Microsoft Teams voice integrations, contact centre solutions and business communications platforms for UK organisations.

If you're already using Teams and want to know whether Teams Phone, Operator Connect, Direct Routing, 8x8, 3CX, Gamma or Zoom Phone is the right fit, we'll give you a straight answer.

No jargon. No overcomplication.

Contact West Pier Technologies today to review your Microsoft Teams phone system options.

Microsoft Teams Phone System Integration: How to Make It Work Properly with 8x8, 3CX, Gamma and Zoom

Why Teams Is Suddenly Part of the Phone System Conversation

Can Microsoft Teams Replace Your Phone System?