VoIP vs Microsoft Teams Calling: Which Is Better for UK Businesses?

If you are evaluating the future of your business communications, you are likely asking a critical question: VoIP vs Microsoft Teams Calling: which is better for UK businesses?

The short answer is that the right choice depends entirely on your company size, existing software, and calling volume. Microsoft Teams Phone is often suitable for businesses already deeply embedded in the Microsoft 365 ecosystem with low-volume, internal-heavy calling needs. Hosted VoIP, including dedicated platforms such as 3CX, is often better suited to sales teams, contact centres, and businesses requiring advanced CRM integration, granular call routing, and strict call recording controls.

For UK businesses, making this decision is becoming increasingly urgent. The UK PSTN switch-off is expected by January 2027, meaning businesses still using ISDN and traditional analogue phone lines need to plan their migration to digital services. You can read more about this in our guide to the copper network switch-off. For official guidance, Ofcom also explains the move from traditional landlines to digital phone services in its future of landline calls guidance.

This guide will break down the features, true costs, and technical requirements of both options, helping you make the most cost-effective and future-proof decision for your organisation.

Quick comparison snapshot

Key differences between a business phone system and Teams Phone

A traditional or dedicated business phone system is built from the ground up to handle external voice calls, offering extensive PBX features, call transfer protocols, and hunt groups. If you are new to this area, our guide to cloud-based phone systems explains how modern internet-based phone systems work.

Microsoft Teams Phone, conversely, is an add-on to a collaboration tool. To make it work as a full business phone system, you must navigate several licensing layers. You may need a base Microsoft 365 licence, a Teams Phone licence, and PSTN connectivity through a Microsoft Calling Plan, Operator Connect, or Direct Routing. Microsoft explains these options in its official Teams PSTN connectivity guidance.

While dedicated VoIP platforms give you more flexible carrier options, Microsoft Teams Calling keeps more of your communication within the Microsoft ecosystem.

Decision criteria for choosing business telephony

When choosing between cloud telephony options, UK businesses should evaluate the following must-have criteria:

• Call quality and internet connection readiness: Your broadband connection dictates your sound quality.
• Integration with business tools: How well does the system link with your CRM or helpdesk?
• Compliance and call recording requirements: Does the system support your recording, retention, and access control needs?
• Total cost of ownership: What is the true per-user cost over three years?

If cost is a major factor, it is also worth reading our guide on how much VoIP costs in the UK.

Feature comparison: cloud telephony, hosted VoIP, and Teams Phone

When comparing features, it is important to weigh core voice functionality against the monthly cost per user.

Call quality and internet connection

Voice over Internet Protocol relies entirely on your internet connection. For strong call quality, you need sufficient bandwidth, stable latency, and properly configured network prioritisation. Both hosted VoIP and Teams Phone can offer excellent call quality, provided your broadband and local network are configured correctly.

If you are unsure whether your connection is suitable, our guide on business broadband costs explains the different connection types available, while our article on scalable broadband solutions explains how to plan for long-term growth.

Calling plans and pricing

The total cost for Microsoft Teams Phone can vary depending on your Microsoft 365 licence, Teams Phone add-on, calling plan, and whether you use Direct Routing or Operator Connect.

Dedicated VoIP systems often provide better value for businesses focused primarily on voice communications, especially where inclusive UK calling, call routing, and reporting are required. To understand the wider cost picture, read our guide on how to reduce business telecom costs.

Desk phones and device support

While many modern teams use softphones and mobile apps, physical handsets are still vital for reception desks, sales teams, and support environments.

Hosted VoIP supports a wide range of common SIP desk phones, while Teams Phone works best with Teams-certified devices. Both systems offer mobile apps, which can be especially useful for remote and hybrid teams. If mobile flexibility is important to your business, our guide to choosing the right business mobile plan may also help.

Direct Routing, integrations, and business tools

Integration capabilities can transform a phone system from a cost centre into a productivity tool. Dedicated VoIP systems often offer deeper integrations with business applications, enabling click-to-dial, automatic call logging, and better reporting.

Microsoft Teams Phone integrates well with Microsoft tools such as Outlook and Dynamics. If you require Microsoft Teams but want more flexible external calling, Direct Routing through a managed provider can be a practical route.

Call recording and compliance

For some businesses, call recording is essential for training, dispute resolution, or regulatory requirements. Dedicated VoIP platforms often include native call recording, call analytics, and easier retrieval of recordings.

If reporting and monitoring are important to your business, read our guide on what call analytics is.

Hosted VoIP UK: strengths, weaknesses, and use cases

Strengths

• Advanced call queues, auto attendants, and hunt groups.
• Competitive per-user costs and inclusive UK calling options.
• Strong CRM integration and reporting tools.
• Flexible setup for office-based, hybrid, and remote teams.

Weaknesses

• May require managing a separate app if your team already uses Teams heavily.
• Requires a reliable broadband connection for the best call quality.

When to choose hosted VoIP

Choose hosted VoIP if your business needs advanced telephony features, richer reporting, flexible carrier control, and strong customer interaction tools. It is especially useful for sales teams, support teams, estate agents, recruitment agencies, and contact-centre-style environments.

You can explore this further in our guide to cost-effective VoIP solutions for businesses.

When to choose Teams Phone

Strengths

• Keeps communication inside the Microsoft Teams environment.
• Useful for internal calls, meetings, chat, and document collaboration.
• Works well for businesses already standardised on Microsoft 365.

Weaknesses

• Can become expensive due to multiple licence layers.
• Advanced PBX, contact centre, and reporting features may require extra tools.
• Third-party CRM integrations may be more limited than dedicated VoIP platforms.

When to choose Teams Phone

Choose Teams Phone if Microsoft 365 is already central to your daily operations and your staff primarily make low-volume or internal calls.

Hybrid options: hosted VoIP integrated with Teams via Direct Routing

You do not necessarily have to choose one or the other. By using Direct Routing, you can connect a hosted VoIP platform to Microsoft Teams. This hybrid approach allows staff to use the familiar Teams interface while a dedicated VoIP provider manages call routing, SIP trunk connectivity, and external calling.

If your current setup uses older telephony infrastructure, our guide to SIP trunks may help explain how modern voice connectivity works.

Migration and PSTN switch-off checklist

With the PSTN switch-off approaching, switching VoIP providers or upgrading from traditional lines requires a clear plan:

• Create an inventory of current phone numbers, ISDN lines, and alarm or lift lines.
• Test internet connection speeds and peak concurrent call capacity.
• Plan number porting steps so you can retain your business numbers.
• Schedule staff training, desk phone provisioning, and soft-launch testing.

If you need to keep existing numbers, read our guide on what a number port is. You may also find our article on when the copper switch-off is happening useful for planning.

Pricing and procurement tips

When sourcing quotes for a business phone system:

• Request transparent quotes detailing all licence layers, especially for Teams.
• Include hardware costs and one-off setup fees.
• Negotiate Service Level Agreements and UK support response times.
• Check whether broadband, VoIP, and mobile services can be bundled for better value.

For a broader setup view, read our guide on building a reliable business communication system with VoIP and broadband.

Short FAQ to address common buyer concerns

Is VoIP worth it for small businesses?

Yes. VoIP can reduce call costs, enable remote working through mobile apps, and provide enterprise-grade features such as auto attendants, call routing, and voicemail-to-email at a lower cost than many traditional phone systems.

Can Teams replace VoIP?

Yes, Microsoft Teams can replace a traditional VoIP system when used with Teams Phone and suitable PSTN connectivity. However, businesses needing advanced call centre features, deeper reporting, and more flexible call routing may prefer a dedicated VoIP platform.

Which VoIP provider is the best in the UK?

The best provider depends on your business needs. Look for transparent pricing, UK-based support, strong uptime, number porting support, and the ability to scale as your business grows.

Can I call a UK landline using Microsoft Teams?

Yes. By adding Teams Phone and suitable PSTN connectivity through Microsoft Calling Plans, Operator Connect, or Direct Routing, you can make and receive external calls to UK landlines and mobiles directly within Teams.

Conclusion and recommendation

Both Microsoft Teams Calling and hosted VoIP platforms can help UK businesses move away from traditional phone lines before the PSTN switch-off.

Choose Microsoft Teams Phone if your business already works heavily inside Microsoft 365 and mainly needs simple calling alongside internal collaboration.

Choose hosted VoIP if you need advanced call routing, CRM integration, call recording, reporting, flexible user management, and lower monthly telephony costs.

Speak to Digital Exchange about VoIP, Teams Phone, or Direct Routing

If you are not sure whether VoIP, Microsoft Teams Calling, or a hybrid Direct Routing setup is right for your business, Digital Exchange can help you make the decision with confidence.

We help UK SMEs review their current phone systems, assess broadband readiness, plan number porting, and migrate to modern cloud-based communications with minimal disruption.

Whether you need a dedicated hosted VoIP platform, a Teams-integrated calling solution, or advice on preparing for the 2027 PSTN switch-off, our team can design a practical, cost-effective setup around your business.

Ready to modernise your phone system? Contact Digital Exchange today to request a tailored telephony audit, compare your options, and plan a smooth migration to a future-ready business communication system.