Best UK VoIP Providers | Business Comparison
The best UK VoIP providers for business are Gamma Horizon, 3CX, RingCentral, Microsoft Teams Phone, and 8x8. Each provider leads in a different dimension: carrier quality, cost efficiency, integrations, Microsoft 365 alignment, and contact centre capability. This comparison helps UK businesses identify the right match.
Nathan Hill-Haimes
Technical Director
Evaluating the Best UK VoIP Providers for Business
The term "best" is context-dependent in VoIP — the platform that is best for a 200-user financial services firm is different from what is best for a 10-person professional services business. This comparison focuses on the dimensions that matter most for UK SMEs and mid-market businesses: reliability, features, pricing, support, and fit with existing technology.
Gamma Horizon: Best for UK Carrier Reliability
Gamma Horizon is the hosted VoIP platform of choice for many UK managed IT providers and telecoms resellers. It is built on Cisco Broadworks — carrier-grade infrastructure used by major telcos globally — and delivered through an accredited reseller network rather than direct to business.
Why businesses choose it: Consistent, reliable call quality backed by UK carrier infrastructure. Comprehensive feature set covering everything an SME needs. Strong reseller support model means businesses get managed setup and ongoing account management.
Pricing: £12–£18 per user per month. Typically includes unlimited UK landline and mobile calls.
Best suited to: UK businesses of 5–200 users wanting a fully managed, reliable hosted phone system without managing the technology themselves.
3CX: Best for Value and Flexibility
3CX is a software PBX that runs in the cloud, on a private server, or on-premise. It offers one of the most feature-rich platforms at the lowest price points in the market. The trade-off is that it requires more active management than a fully managed hosted service.
Why businesses choose it: Lowest total cost of ownership at most user counts. Full feature depth including video conferencing, web client, and CRM integrations. Flexible deployment suits businesses with specific data residency or infrastructure requirements.
Pricing: From £8–£14 per user per month (hosted). Separate SIP carrier costs apply.
Best suited to: Businesses with IT resource in-house or through a managed IT provider who can manage the platform configuration.
RingCentral: Best for Integration Breadth
RingCentral is the market-leading UCaaS platform globally, with over 250 application integrations. Its UK operation is established and compliant with UK data protection requirements.
Why businesses choose it: Unmatched integration library — Salesforce, HubSpot, Zendesk, ServiceNow, and hundreds more. Single platform for calls, messages, and video. Five-nines uptime SLA.
Pricing: £15–£25 per user per month.
Best suited to: Businesses where CRM and business application integration is a primary requirement. Higher price justified by integration capabilities.
Microsoft Teams Phone: Best for Microsoft 365 Users
Microsoft Teams Phone turns Teams into a complete business phone system. For businesses already invested in Microsoft 365, it represents the most logical path to modern telephony.
Why businesses choose it: No separate application — calling happens through Teams, which staff already use. Deep integration with M365 apps. Competitive total cost. Microsoft's global infrastructure.
Pricing: £11–£21 per user per month combined (licence + calling plan).
Best suited to: Microsoft 365 users on Business Premium, E3, or E5 who want to use Teams as their phone system.
8x8: Best for Contact Centre Operations
8x8's X-series platform scales from basic UCaaS to full contact centre capability within a single platform. Its contact centre features are well regarded, and the unlimited international calling on higher plans is valuable for global businesses.
Why businesses choose it: Strong contact centre features without requiring a separate specialist platform. Unlimited calls to 40+ countries. Good analytics and supervisor tooling.
Pricing: £12–£20 per user per month (X2–X4). Contact centre from higher price points.
Best suited to: Businesses with customer service teams requiring contact centre functionality alongside standard UCaaS.
Making the Right Choice
The best UK VoIP provider is the one that best matches your requirements, your existing technology, and your budget. AMVIA provides independent comparison for UK businesses across all these providers — helping you reach the right decision without the time investment of a full market evaluation.
Which Provider Is Best for Your Business?
AMVIA applies a structured comparison to identify the best UK VoIP provider for your specific requirements, user count, and budget.
Frequently Asked Questions
No. Gamma Horizon is sold exclusively through accredited reseller partners. This means businesses access Gamma through a managed IT provider or telecoms reseller like AMVIA rather than purchasing directly from Gamma. This model typically provides better support and account management than a direct purchase.
RingCentral is a strong platform but is priced at the higher end (£15–£25/user/month) and includes features that many small businesses will not use. For small UK businesses (fewer than 20 users) without specific integration requirements, Gamma Horizon or 3CX typically provide better value.
Yes, fully. With a Teams Phone licence and a calling plan or direct routing arrangement, Teams can make and receive calls to any phone number worldwide, support call queues and auto-attendants, record calls, and provide full call analytics. For Microsoft 365 businesses, it is a complete phone system replacement. <strong>Microsoft Teams Phone has surpassed 26 million PSTN users worldwide</strong> as of December 2025 — up from 20 million in April 2024, representing 30% growth in 20 months. <em>(UC Today)</em>
8x8 X2 is the base UCaaS plan with VoIP, video, and messaging. X4 adds supervisor analytics, call quality reports, and extended storage. Both are aimed at general business use. X6 and above are contact centre products. For most SMEs, X2 covers standard requirements; X4 is worth the upgrade if detailed call analytics are needed.
Free or very low-cost VoIP services (such as consumer apps) are not appropriate for business use — they lack the reliability, features, number portability, and support that business telephony requires. Business VoIP starts at approximately £8 per user per month from reputable providers. Below this price point, quality and reliability compromises are inevitable.
Reputable UK VoIP providers address GDPR through data processing agreements, data residency controls, and security certifications (ISO 27001, SOC 2). UK-native providers (Gamma) store data on UK infrastructure by default. International providers (RingCentral, 8x8) have data residency options for UK customers. Ask any provider specifically about their GDPR compliance documentation before signing.
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