Choosing a UCaaS platform is no longer just about replacing a phone system. For most organisations, it is about how voice, video, messaging, and customer interactions support everyday operations and longer-term plans.
The table below provides a high-level view of how leading platforms are positioned in the UCaaS market. The sections that follow explain why these platforms continue to be shortlisted in real-world UK deployments.
1. Microsoft Teams
Microsoft continues to lead the UCaaS market, driven by its scale, ecosystem, and deep integration with Microsoft 365.
For many UK organisations, Teams has become the default communications layer. When paired with Calling Plans or Direct Routing, it can operate as a full business phone system. Its main strengths sit around collaboration, familiarity, and integration with productivity tools, rather than advanced native telephony.
Best suited for: organisations already standardised on Microsoft 365 that want to consolidate collaboration and calling.
2. 8x8
8x8 is positioned as a Visionary in the Gartner UCaaS Magic Quadrant, with a strong focus on voice, analytics, and unified communications alongside contact centre capabilities.
It is often selected by organisations looking for a single platform that supports both UCaaS and CCaaS. Voice quality, reporting, and operational insight are consistent reasons it appears on shortlists. While collaboration tooling may not be its primary strength, it performs well in voice-first environments.
Best suited for: mid-market and enterprise organisations with voice-heavy or customer-facing teams.
3. Cisco Webex
Cisco Webex continues to score strongly on execution, security, and enterprise readiness.
It is widely used in regulated and large-scale environments where governance, compliance, and reliability are critical. While the user experience can feel more structured than some newer platforms, Webex remains trusted where risk management and operational stability matter most.
Best suited for: large organisations, public sector bodies, and compliance-driven environments.
4. Zoom
Zoom has successfully expanded beyond meetings into voice and messaging, earning its place among UCaaS Leaders.
Its key strength remains ease of use and a familiar user experience. While telephony features are still developing compared to long-established voice platforms, Zoom Phone is now a viable option for many UK businesses, particularly those already using Zoom Meetings.
Best suited for: organisations that prioritise simplicity and video-first collaboration.
5. RingCentral
RingCentral remains one of the most established UCaaS platforms in the market, with broad global reach and a mature feature set.
It continues to perform well in Gartner evaluations due to its scale, reliability, and partner ecosystem. RingCentral is often selected by organisations with distributed teams or international operations that require a consistent and well-supported UCaaS platform.
Best suited for: multi-site and multinational organisations.
Click here for our 2026 guide to planning a UCaaS review.
A note on Gartner and rankings
Gartner Magic Quadrant positioning reflects vendor vision and execution at a specific point in time. It should be used as a guide rather than a buying decision on its own.
In practice, the right UCaaS platform depends on how critical voice is to your business, how complex your call handling requirements are, and whether AI-driven voice and chat will deliver real operational value. If you would like to discuss which platform fits your environment, please get in touch with us.
