3CX vs. Microsoft Teams Phone System: The 2026 Comparison for UK Businesses

The Quick Answer

Microsoft Teams Phone is best suited for organisations prioritising internal collaboration with light telephony needs and budgets for premium per-user licensing. 3CX is the superior choice for cost-conscious UK businesses requiring advanced telephony features—including sophisticated call queues, IVR systems, and contact centre capabilities—with flexible hosting options and no per-user licensing fees.

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Comparison Table: At a Glance

Feature	3CX	Microsoft Teams Phone
Pricing Model	Concurrent call licensing (system-based) – typically £150-£200/year for base system plus per-channel costs (reseller-dependent)	Per-user licensing – £12-£15/user/month (Teams Phone Standard)
Call Queues	Included with visual Call Flow Designer, unlimited queues, advanced routing logic	Basic queues included; enterprise features require Premium licences or third-party add-ons
IVR Capabilities	Full-featured IVR with multi-level menus, custom prompts, time-based routing	Limited auto-attendant functionality; complex IVR requires workarounds
Hosting Options	Self-hosted (on-premises), private cloud, 3CX-hosted cloud, or hybrid deployment	Microsoft Cloud only (Azure-based infrastructure)
Contact Centre Features	Wallboards, real-time reporting, queue analytics, CRM integration included	Requires third-party solutions or Microsoft Digital Contact Center Platform (additional cost)
UK-Specific Support	Available through UK-based resellers and partners with local expertise	Microsoft support with varying response times; telephony support can be complex
PSTN Connectivity	Direct SIP trunk integration with any UK provider	Requires Microsoft Calling Plans or Direct Routing configuration
Setup Complexity	Moderate – requires technical knowledge or reseller assistance	Simpler for existing Microsoft 365 environments
Mobile Apps	Native iOS/Android apps with full feature parity	Teams mobile app (telephony features dependent on licensing)
Compliance	GDPR-compliant with flexible data residency options	GDPR-compliant, data stored in Microsoft's EU datacentres

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Pricing Breakdown: The Cost Realities

Understanding the Licensing Models

The fundamental difference between 3CX and Microsoft Teams Phone lies in how you're charged for telephony services.

3CX Concurrent Call Licensing:

• System licensed based on simultaneous calls rather than user count
• Base system licence covers the PBX software
• Additional costs scale with concurrent call capacity (4, 8, 16, 32, 64, 128+ channels)
• One-year or perpetual licence options available
• Important note: Pricing is reseller-dependent and varies based on hosting choice and support packages

Microsoft Teams Phone Per-User Licensing:

• Every user requiring telephony capabilities needs a Teams Phone licence
• Standard licence: approximately £12-£15 per user per month
• Does not include PSTN connectivity (calling to external numbers)
• Additional Calling Plan required: £4-£12+ per user per month depending on minutes

Real-World Cost Comparison: 50-Person UK Company

Let's examine a typical UK SME with 50 employees where 30 regularly use the phone system, but only 10 concurrent calls happen at peak times.

This calculation demonstrates the dramatic cost advantage of concurrent call licensing for organisations where not every employee needs simultaneous phone access.

Hidden Costs to Consider

3CX:

• Initial setup and configuration (one-time cost, typically £500-£2,000 depending on complexity)
• Server hosting if self-hosting (£20-£100/month) or included in hosted packages
• Optional support packages from resellers
• Hardware phones (optional – softphones included)

Microsoft Teams Phone:

• Direct Routing gateway if avoiding Microsoft Calling Plans (£500-£3,000 setup)
• Session Border Controller (SBC) licensing for Direct Routing
• Third-party contact centre solutions (£15-£50+ per user per month)
• Premium features require additional licences

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Telephony Features & Functionality

Call Flow Control: Flexibility vs. Simplicity

3CX Call Flow Designer (CFD):

The Call Flow Designer represents 3CX's standout feature for businesses requiring sophisticated call routing.

Key capabilities:

• Visual drag-and-drop interface for building call flows
• Unlimited custom routing scenarios based on:
  • Time of day and day of week
  • Caller ID recognition
  • Queue wait times
  • Agent availability
  • Custom database lookups
• Multi-level IVR menus with unlimited options
• Callback queuing to preserve caller position
• Geographic routing based on caller location
• Integration with CRM data for personalised routing

Microsoft Teams Auto Attendant:

Teams provides basic automated answering and call routing functionality suitable for straightforward requirements.

Key capabilities:

• Simple menu navigation (press 1 for sales, 2 for support)
• Business hours scheduling
• Holiday scheduling
• Directory search functionality
• Basic call forwarding rules

Contact Centre Capabilities: Included vs. Add-On

3CX Native Contact Centre Features:

For UK businesses operating sales teams, support desks, or customer service departments, 3CX includes enterprise-grade contact centre functionality as standard.

Included features:

• Real-time wallboards: Live display of queue statistics, agent status, and waiting calls
• Comprehensive reporting: Historical call data, agent performance metrics, queue analytics
• Queue management: Unlimited queues with priority levels, skills-based routing, and wrap-up codes
• Supervisor functions: Silent monitoring, whisper coaching, call barging
• CRM integration: Pop-screen functionality with Salesforce, HubSpot, Zoho, and custom integrations via API
• Outbound campaign management: Preview, progressive, and predictive dialling modes
• Recording: Call recording with on-demand and automatic options

No additional per-user costs for these features—they're part of the core 3CX licence.

Microsoft Teams Contact Centre Approach:

Teams takes a modular approach, requiring additional investment for serious contact centre functionality.

Basic capabilities (included):

• Simple call queues with standard distribution algorithms
• Basic reporting through Teams admin centre
• Call park and retrieve

Enterprise contact centre requires:

• Microsoft Digital Contact Center Platform: New offering combining Teams with Dynamics 365 and Azure AI (significant additional cost, pricing model evolving)
• Third-party solutions: Products like Enghouse CCaaS, Five9, NICE CXone integrate with Teams but add £15-£50+ per agent per month
• Premium licensing: Advanced features may require Teams Phone with Calling Plan or E5 licences

Advanced Telephony Features Comparison

Feature	3CX	Microsoft Teams Phone
Conference Bridging	Unlimited participants (licence-dependent), PIN protection, recording	Teams meetings integration (excellent), but traditional dial-in conferencing requires Audio Conferencing add-on (£4/user/month)
Voicemail to Email	Included with MP3 attachments	Included with cloud voicemail
Call Recording	Built-in, on-demand or automatic, unlimited storage (self-hosted)	Requires compliance recording solutions (third-party) for quality/training purposes
Hot Desking	Native support for shared desk phones	Limited – primarily designed for personal devices
Fax over IP	T.38 fax support included	Not natively supported – requires third-party integration
Paging/Intercom	Full support for overhead paging and desk phone intercom	Limited to software-based Teams calls

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PSTN Connectivity: How You Connect to the Outside World

3CX SIP Trunking

3CX's carrier-agnostic approach provides maximum flexibility for UK businesses.

Benefits:

• Choice of provider: Connect to any UK SIP trunk provider (Voiceflex, Gamma, Gradwell, Vonage, BT, etc.)
• Competitive pricing: Shop around for the best rates – UK landline calls from 0.5p/minute, mobiles from 3p/minute
• Number portability: Bring existing UK geographic, 0800, 0845, and 03 numbers
• Resilience: Configure multiple trunk providers for automatic failover
• International calling: Negotiate direct rates with providers or use least-cost routing

Microsoft Teams Phone PSTN Options

Microsoft offers two primary routes to external calling:

Option 1: Microsoft Calling Plans

• Domestic Calling Plan: 1,200 UK minutes per user per month (approximately £8/user/month)
• International Calling Plan: UK minutes plus international destinations (approximately £12-£15/user/month)

Pros: Simple to deploy, Microsoft manages everything, includes some emergency calling
Cons: Limited flexibility, higher per-minute costs for heavy users, not available in all UK regions historically

Option 2: Direct Routing

• Connect Teams to your own SIP trunk provider via a Session Border Controller (SBC)

Pros: Choose your carrier, potentially lower costs, retain existing numbers and relationships
Cons: Requires technical expertise, SBC hardware/software costs, more complex troubleshooting

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The Hybrid Approach: 3CX with Microsoft Teams

One of the most sophisticated deployment strategies for UK businesses is using 3CX and Microsoft Teams in tandem—leveraging each platform's strengths.

Why Consider a Hybrid Solution?

The business challenge:

• Your organisation has invested in Microsoft 365 and users love Teams for chat, file sharing, and video meetings
• However, Teams Phone licensing costs are prohibitive for your entire organisation
• You need advanced telephony features (contact centre, complex IVR) that Teams doesn't provide cost-effectively
• Different departments have different needs (e.g., office staff need collaboration; sales team needs advanced call handling)

How 3CX-Teams Integration Works

Architecture:

• 3CX acts as the primary PBX, handling all PSTN connectivity and advanced telephony
• Microsoft Teams remains the collaboration platform for chat and meetings
• Users can click-to-call from Teams, with calls routed through 3CX
• Presence synchronisation shows availability across both platforms

Implementation options:

Option A: 3CX as SBC for Teams Direct Routing

• 3CX functions as the Session Border Controller
• Teams users make/receive calls via 3CX's PSTN connectivity
• Maintains Teams Phone interface for end-users
• Benefits from 3CX's lower connectivity costs

Option B: Teams for Collaboration + 3CX for Telephony

• Office workers use Teams for internal communication (no Teams Phone licence required)
• Sales/support staff use 3CX softphone or desk phones for external calling
• Both systems coexist independently
• Lower total licensing costs

Option C: 3CX with Teams Web Client Integration

• 3CX V20 includes Teams integration features
• Click-to-call from Teams contacts to 3CX
• Unified presence status
• Best-of-both-worlds user experience

Cost Benefits of the Hybrid Approach

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Deployment & Hosting: Flexibility vs. Simplicity

3CX Hosting Options

Self-Hosted (On-Premises):

• Install on Windows, Linux, or via appliance
• Full control over data and infrastructure
• One-time licence cost model available
• Best for: Organisations with existing IT infrastructure, data sovereignty requirements, or technical capability

3CX-Hosted Cloud:

• Fully managed by 3CX in their datacentres
• Annual subscription includes hosting
• Automatic updates and maintenance
• Best for: Businesses wanting 3CX features without server management

Partner-Hosted Cloud:

• UK-based resellers offer hosted 3CX instances
• Local support and SLAs
• Often bundled with SIP trunks and numbers
• Best for: SMEs wanting local support and simplified billing

Hybrid Deployment:

• Main office runs on-premises 3CX
• Branch offices connect via cloud
• Mix deployment models based on site requirements

Microsoft Teams Phone Hosting

Microsoft Cloud Only:

• Teams Phone operates exclusively in Microsoft's Azure cloud infrastructure
• UK/EU datacentre options for data residency
• Microsoft manages all infrastructure and updates
• No self-hosted option available

Implications:

• Pro: Zero infrastructure management for IT teams
• Pro: Automatic feature updates and security patches
• Con: Complete dependency on Microsoft's platform
• Con: No option for air-gapped or fully on-premises deployment

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User Experience & Interface

Desktop & Mobile Applications

3CX:

• Web-based client: No installation required, works in any modern browser
• Desktop apps: Windows, macOS, Linux native applications
• Mobile apps: iOS and Android with full feature parity
• Desk phones: Support for Yealink, Fanvil, Cisco, and other SIP phones
• Interface focus: Telephony-first design with call controls prominent

Microsoft Teams:

• Unified app: Single Teams application for chat, calls, meetings, and files
• Desktop apps: Windows and macOS (deeply integrated with OS)
• Mobile apps: iOS and Android (excellent for meetings, adequate for telephony)
• Desk phone support: Limited certified devices (expensive Teams-certified phones required)
• Interface focus: Collaboration-first with telephony as secondary function

Administration & Management

3CX:

• Web-based administration console
• Granular control over every system parameter
• Visual Call Flow Designer (mentioned earlier)
• Detailed CDR (Call Detail Records) with filtering
• Real-time dashboard showing system status
• Learning curve: Moderate – requires understanding of telephony concepts

Microsoft Teams:

• Teams Admin Centre (web-based)
• PowerShell for advanced configuration
• Integrated with broader Microsoft 365 admin tools
• Policy-based management (assign features via policies)
• Learning curve: Gentle for basic setup, steep for complex scenarios

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Integration & API Capabilities

3CX Integration Ecosystem

Native integrations:

• CRM platforms: Salesforce, Microsoft Dynamics, HubSpot, Zoho, Freshsales, SugarCRM
• Helpdesk systems: Zendesk, Freshdesk, ServiceNow
• Microsoft 365: Outlook contacts, Teams presence (as discussed)
• Google Workspace: Contacts synchronisation

API capabilities:

• RESTful API for custom integrations
• WebRTC SDK for embedding calls in web applications
• Call control API for third-party applications
• Webhook support for real-time events

Microsoft Teams Integration Ecosystem

Native Microsoft ecosystem:

• Seamless integration: SharePoint, OneDrive, Outlook, OneNote, Planner
• Power Platform: Power Automate workflows, Power Apps, Power BI dashboards
• Dynamics 365: Deep integration with Microsoft's CRM/ERP suite

Third-party integrations:

• Extensive marketplace of Teams apps
• Many business applications offer Teams integration
• Graph API provides programmatic access

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Support & Community: UK Considerations

3CX Support Structure

Official 3CX support:

• Tier-based support plans (Bronze, Silver, Gold, Platinum)
• Community forum (active, with 3CX staff participation)
• Extensive documentation and knowledge base
• UK-specific: No direct 3CX support presence in UK

UK Reseller Support:

• Most UK businesses purchase through certified partners
• Resellers provide frontline support
• Local, timezone-appropriate assistance
• Varying quality depending on partner choice

Microsoft Teams Phone Support

Microsoft support tiers:

• Basic support included with subscriptions
• Premier/Unified support for enterprise customers (additional cost)
• FastTrack assistance for large deployments

Support challenges:

• Complex telephony issues may require escalation through multiple tiers
• Support engineers may have limited PSTN/telephony expertise
• UK businesses may experience timezone delays for complex issues

Advantages:

• Established support infrastructure
• Integration with broader Microsoft 365 support
• Extensive online documentation

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Security & Compliance: GDPR and Beyond

3CX Security Features

Encryption:

• TLS encryption for signalling
• SRTP encryption for voice media
• HTTPS for web clients and administration
• VPN support for remote extensions

Access control:

• Role-based admin permissions
• Two-factor authentication (2FA) for admin portal
• IP whitelisting for SIP trunks
• Firewall rules and security recommendations

GDPR compliance:

• Self-hosted option keeps all data on-premises (full control)
• Cloud deployments: Data processing agreements available
• Call recording storage under your control
• Right to erasure supported

Microsoft Teams Phone Security

Enterprise-grade security:

• End-to-end encryption for peer-to-peer calls
• Data encrypted at rest in Microsoft datacentres
• Advanced Threat Protection integration
• Conditional access policies

Compliance certifications:

• ISO 27001, SOC 2, GDPR-compliant
• UK/EU data residency options
• Regular third-party audits

GDPR considerations:

• Microsoft acts as data processor
• Data Processing Addendum included with enterprise agreements
• Data Subject Requests supported through compliance centre

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Reliability & Business Continuity

3CX Resilience Options

High availability configurations:

• Active-passive failover for on-premises deployments
• Geographic redundancy with hosted solutions
• Automatic trunk failover to backup SIP providers
• Mobile app continuity (extensions work even if main PBX is down)

Disaster recovery:

• Daily backup recommendations
• Quick restoration procedures
• Survivability options for branch offices

Microsoft Teams Phone Reliability

Microsoft's infrastructure:

• 99.9% uptime SLA for Teams services
• Global Content Delivery Network (CDN)
• Automatic geographic redundancy
• No single point of failure in Microsoft's architecture

Considerations:

• Entire dependency on Microsoft's service availability
• Historical outages have affected Teams (though infrequent)
• No option for local backup system

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Migration & Implementation Complexity

Migrating to 3CX

Typical migration path:

1. Audit existing phone system and number inventory
2. Choose hosting option (self-hosted, partner-hosted, 3CX cloud)
3. Select UK SIP trunk provider and port numbers (typically 5-15 working days)
4. Configure 3CX system (call flows, extensions, queues)
5. Deploy handsets or softphones
6. User training
7. Cutover (often done outside business hours)

Migrating to Teams Phone

Typical migration path:

1. Ensure Microsoft 365 tenant is configured
2. Purchase Teams Phone licences and Calling Plans (or configure Direct Routing)
3. Port numbers to Microsoft or configure SBC
4. Assign phone numbers to users
5. Configure policies (calling, dial plan, emergency calling)
6. User training (often minimal if already using Teams)
7. Cutover

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Future-Proofing: Platform Evolution

3CX Development Roadmap

Recent innovations (2024-2026):

• Enhanced Microsoft Teams integration
• AI-powered voicemail transcription
• Improved mobile app performance
• WebRTC enhancements for browser-based calling
• Cloud PBX improvements

Future direction:

• Continued focus on SME and mid-market
• Enhanced AI features (sentiment analysis, call summarisation)
• Deeper CRM integrations
• Maintained cost-effectiveness as core value proposition

Microsoft Teams Phone Evolution

Recent developments:

• Teams Phone Mobile (mobile network integration)
• Operator Connect expansion (simplified carrier integration)
• Enhanced queue analytics
• AI-powered features (live captions, transcription, meeting summaries)

Future direction:

• Deeper AI integration across calling features
• Continued convergence with Microsoft 365 Copilot
• Enhanced integration with Dynamics 365 Customer Service
• Premium features likely to remain at premium pricing

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Real-World Scenarios: Which Platform Fits?

Scenario A: 8-Person Marketing Agency in Manchester

Profile:

• Internal collaboration is primary need
• Occasional client calls
• Already using Microsoft 365
• Limited IT resources

Scenario B: 45-Person Insurance Broker in London

Profile:

• 15-person sales team making 50+ external calls daily
• 5-person customer service handling inbound queries
• Complex call routing needed (new business vs. renewals vs. claims)
• Existing Microsoft 365 for email

Implementation approach: Retain Microsoft 365 for email and document collaboration; Deploy 3CX for all telephony; Sales team uses 3CX desk phones or softphones; Consider Teams integration for presence synchronisation

Scenario C: 120-Person Managed Service Provider (MSP) in Birmingham

Profile:

• 30-person helpdesk requiring queue management and reporting
• 40 field engineers needing mobile calling
• 50 office staff for administration and sales
• Existing Microsoft E3 licences
• Multiple offices across UK

Scenario D: 200-Person Financial Services Firm in Edinburgh

Profile:

• Strict compliance and recording requirements
• Deep investment in Microsoft ecosystem (E5 licences, Dynamics 365)
• 24/7 operations with shift patterns
• Enterprise-grade security requirements

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Verdict: Which Platform is Right for Your UK Business?

Choose Microsoft Teams Phone if:

• You have fewer than 15 users with light telephony needs (primarily internal collaboration)
• You're deeply invested in the Microsoft 365 ecosystem and want a single-vendor solution
• Simplicity is paramount and you lack in-house IT expertise
• Your primary use case is collaboration with telephony as a secondary function
• You have budget for per-user licensing and value Microsoft's enterprise-grade infrastructure
• Your users are already Teams-dependent and introducing another platform would create friction

Typical UK businesses: Professional services firms, small creative agencies, consultancies, businesses with primarily knowledge workers

Choose 3CX if:

• You have 15+ users or anticipate growth
• You have sales, support, or customer service teams requiring advanced call handling
• Cost optimisation is important and concurrent call licensing makes financial sense
• You need contact centre features (queues, wallboards, reporting) without paying for add-ons
• You want hosting flexibility (self-hosted, partner-hosted, or cloud options)
• You require complex call routing with IVR, time-based routing, or skills-based distribution
• You prefer carrier independence and want to choose your UK SIP trunk provider

Typical UK businesses: Sales organisations, contact centres, recruitment agencies, insurance brokers, MSPs, businesses with high call volumes

Choose a Hybrid Approach (3CX + Teams) if:

• You have mixed user needs (office staff need collaboration; sales/support need advanced telephony)
• You want to leverage existing Microsoft 365 licences while avoiding Teams Phone costs
• You need enterprise contact centre capabilities but want Teams for collaboration
• You have 50+ users with varying telephony requirements
• You have technical resources to manage integration between platforms

Typical UK businesses: Growing SMEs, organisations with distinct departments, MSPs, businesses transitioning from legacy systems

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Key Takeaways for UK Decision-Makers

Financial Reality Check

For most UK SMEs with significant telephony needs (20+ users, sales/support functions), 3CX delivers 60-80% cost savings compared to Microsoft Teams Phone while providing superior call handling capabilities.

Feature Sophistication

If your business requires anything beyond basic call answering and forwarding—queue management, IVR systems, contact centre reporting—3CX includes these features as standard, whereas Teams requires expensive add-ons or third-party solutions.

The Microsoft Tax

Teams Phone makes sense when you're paying for it anyway (included in some E5 licences) or when your organisation values Microsoft's single-vendor simplicity above cost considerations. For businesses paying separately for telephony, the per-user licensing model becomes prohibitively expensive as headcount grows.

UK PSTN Switch Off Preparedness

Both platforms are fully IP-based and ready for the UK's PSTN/ISDN shutdown completing in January 2027. 3CX's carrier-agnostic approach provides more flexibility in choosing UK SIP trunk providers positioned for the transition.

Support Considerations

3CX users depend on reseller quality—choose a reputable UK partner with strong support credentials. Teams Phone users depend on Microsoft's support structure—which can be bureaucratic for complex telephony issues.

Implementation Approach

Don't rush the decision. Many UK businesses benefit from:

• Starting with a pilot: Deploy 3CX or Teams Phone for a department before full rollout
• Hybrid deployment: Use both platforms strategically based on user needs
• Phased migration: Transition from legacy systems gradually, testing functionality thoroughly

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Next Steps: Making Your Decision

Assessment Questions to Ask Internally

Financial:

• What is our monthly telephony budget?
• How many users need external calling capability?
• What are our peak concurrent call volumes?
• Can we justify per-user licensing or would concurrent call licensing save significantly?

Functional:

• Do we operate a contact centre or support desk?
• How complex are our call routing requirements?
• Do we need detailed call reporting and analytics?
• Will we need CRM integration with telephony?

Strategic:

• How invested are we in the Microsoft ecosystem?
• Do we have in-house IT resources to manage telephony infrastructure?
• What is our growth trajectory over the next 3-5 years?
• Do we prefer cloud-only or want hosting flexibility?

Recommended Action Plan

1. Audit current telephony usage: Understand call volumes, patterns, and feature utilisation
2. Calculate total cost of ownership: Factor in licences, hardware, support, and implementation for both platforms
3. Request demos: See both platforms in action with UK-specific scenarios
4. Consult with specialists: Speak with 3CX resellers and Microsoft partners about your specific requirements
5. Consider a proof of concept: Test with a small user group before committing organisation-wide

Conclusion

The 3CX vs. Microsoft Teams Phone decision fundamentally comes down to your organisation's priorities: collaboration-first simplicity versus telephony-first functionality and cost-effectiveness.

Microsoft Teams Phone excels when telephony is secondary to collaboration, your organisation is small, or you're willing to pay premium pricing for single-vendor convenience within the Microsoft ecosystem.

3CX dominates when telephony is a core business function, you operate sales or support teams, you need contact centre capabilities, or you're a cost-conscious UK business seeking maximum value without sacrificing features.

For many UK businesses, the optimal solution isn't either/or—it's a strategic hybrid that uses Teams for what it does best (collaboration) and 3CX for what it does best (telephony), delivering the best of both worlds while optimising costs.

The UK telephony landscape in 2026 offers more choice than ever. Make your decision based on your specific business requirements, growth plans, and budget realities—not on vendor marketing or the assumption that "everyone uses Teams." The right platform is the one that serves your business needs most effectively, both today and as you grow.